家世及投唐

安思順父是胡人將軍安波注。安波注之弟安延偃娶巫師阿史德氏，後者已有子軋犖山，被安延偃收養，改名安祿山。一次，安延偃所部潰散，安祿山、安思順、安延偃逃到唐朝境內。將軍安道買次子安貞節正擔任嵐州別駕，于是他們就投靠了安貞節。安貞節厚待安延偃，約定兩家子輩為兄弟，故安祿山與安思順約為兄弟。

為將生涯

開元二年（714年）七月，吐蕃入侵臨洮軍，又游寇蘭州、渭州，掠奪群畜，玄宗起用薛訥攝左羽林將軍、隴右防禦使，率杜賓客、郭知運、王晙、安思順以抵禦之，太子右衛率、豐安軍使王海賓為先鋒，諸將嫉恨他有功，按兵不救，致其寡不敵眾陣亡。最終唐軍苦戰得勝。九年（721年）四月，朝廷下詔賞賜抗擊吐蕃功臣，安思順以右監門衛將軍、臨洮軍使升任洮州刺史兼充莫門軍使，賜物二百段，銀三百兩，錢五十萬。

大約天寶五載（746年），安思順、哥舒翰分別任王海賓之子河西、隴右節度使王忠嗣屬下大斗軍正副使，互不相讓。

安思順雖然有才有寵，但也通過巴結宦官驃騎大將軍高力士才得以官運亨通。天寶六載（747年）十一月，唐玄宗調動節度使，改任時任朔方節度使的安思順充河西節度使，判武威郡事。九載（750年）八月，他權知朔方節度事。

十載（751年）正月，朔方節度使改由宰相李林甫遙領，時任河西節度使、鴻臚卿員外置同正員、攝御史中丞、權知朔方節度事的安思順罷朔方節度使，加特進，攝御史大夫，一個兒子得到授官，其餘官職如故。四月，唐玄宗見了時任安西節度使高句麗族將領高仙芝後，賞識他，下令任高仙芝為河西節度使。但安思順指使手下胡人首領割耳朵、劃破臉，請求玄宗讓他留任。監察御史裴周南也奏聞朝廷，于是玄宗下詔安思順留任，以高仙芝為右羽林大將軍。

十一載（752年）三月，突厥首領朔方副使李獻忠（阿布思）叛亂期間，李林甫忙于和同僚陳希烈爭權，不想離開京城長安去平叛，辭朔方節度使，推薦安思順接任，玄宗准奏。大約同年，安思順不再擔任河西節度使。安思順曾率宗羲仲等破魚海，攻占五城。同年，他奏請調河西節度副使李光弼為單于都護府副大都護。

同時，安思順、時任范陽節度使的安祿山與時任隴右節度使哥舒翰不合。玄宗試圖改善他們的關係，讓他們約為兄弟，當年十二月召三人到長安，讓高力士為三人設宴，希望他們和解，但席間哥舒翰和安祿山卻陷入激烈爭論，他們之間的關係不但沒有改善，反而惡化。

十二載（753年），安思順聯合北庭都護程千里，遣折衝果毅渾瑊以偏師深入葛祿部，經過狐媚磧，掠奪特羅斯山，大破阿布思部眾。同年，安思順奏請將陰山北麓的橫塞軍移置于南麓的大同川之西，詔改其名為天德軍，安思順建其北城，周圍四一十二里，高四丈，下闊一丈七尺，于十四載（755年）完工。十三載（754年）三月，阿布思被押送京城斬首示眾。

同年，李光弼被任為朔方兵馬使，安思順奏其為副使、知留後事，愛其材，想把女兒嫁給他，李光弼推辭不過，稱病辭官。這可能是因為李光弼感念被李林甫誣陷暴死的故帥王忠嗣，而安思順是李林甫所薦，李林甫又稱美安祿山，李光弼懷疑安思順為李林甫黨羽，才拒絕其示好。哥舒翰聞知，認為李光弼有節操，奏請讓李光弼回京師。左領軍大將軍同正員、特進僕固懷恩因善格鬥、了解各少數民族情況、有統御之材，被安思順委為心腹。安思順引匡城尉敬羽于自己的幕府。表延王府參軍杜鴻漸為判官。

十四載（755年），詔命追贈安思順祖父左衛鈐衛郎將安某為武部尚書，亡父右羽林大將軍安波注為太子太師。

冤死

安思順注意到安祿山因被繼李林甫為相且是玄宗最得寵的妃子楊貴妃堂兄的楊國忠激怒，正計劃作亂。他入朝將此事奏明玄宗，玄宗不信，但仍相信安思順是忠誠的。十四載（755年）十一月，安祿山果然作亂，玄宗也因安思順先前有奏，沒懲罰安思順，召時任朔方節度副使兼靈武郡太守、御史大夫的他回長安任戶部尚書。安思順的弟弟安元貞被任為太僕卿。安思順的部下朔方右廂兵馬使、九原太守郭子儀被任為朔方節度使。當時郭子儀、李光弼都是牙門都將，彼此不合，即使同盤飲食也斜眼相視不說話。郭子儀代任後，與李光弼為了平叛而放棄私憤以忠義互勉。

但哥舒翰仍然敵視安思順。他很快受任為元帥統軍討伐安祿山，知道自己手握重兵，自己請奏的事玄宗不會違背。十五載（756年），哥舒翰部下馬軍都將王思禮勸哥舒翰謀殺安思順。于是哥舒翰偽造了一封安祿山寫給安思順的信，讓使者在關門被俘，再把信及彈劾安思順七大罪的表文呈給玄宗。三月，時任開府儀同三司兼工部尚書的安思順及安元貞被下詔賜死，家族被流放到嶺南。天下以為冤。楊國忠不能相救，也因此開始畏懼哥舒翰。

唐代宗廣德二年（764年）正月，時任河東副元帥等職的郭子儀上表請求為安思順兄弟昭雪。

注釋

Background and flight to Tang territory

An Sishun's father's name might have been An Daomai (安道買), and appeared to be of Tujue extraction. An Daomai's brother An Yanyan (安延偃) had married a sorceress, Lady Ashide, who already had a son named Galuoshan, whom An Yanyan adopted and renamed An Lushan. At some point, An Yanyan's tribe suffered a catastrophe, and An Lushan, An Sishun, and possibly An Yanyan, fled to Tang Dynasty territory. At that time, another son of An Daomai's, An Zhenjie (安貞節), was serving as advisor to the Tang prefect of Lan Prefecture (嵐州, in modern Lüliang, Shanxi), and so they settled with An Zhenjie.

Career as general

As of 747, An Sishun was serving as the military governor (jiedushi) of Shuofang Circuit (朔方, headquartered in modern Yinchuan, Ningxia), when, as a part of governor movements, Emperor Xuanzong made him the military governor of Hexi Circuit (河西, headquartered in modern Wuwei, Gansu), as well as acting governor of Wuwei Commandery. In 750, he assumed the military governorship of Shuofang as well.

In 751, after Emperor Xuanzong met with and was impressed by the ethnically Goguryeo general Gao Xianzhi, who was then military governor of Anxi Circuit (安西, headquartered in modern Aksu Prefecture, Xinjiang), he issued an order making Gao the military governor at Hexi. However, An encouraged the non-Han chieftains under his command to cut off their ears and lacerate their faces and request that Emperor Xuanzong allow An to remain at Hexi, and Emperor Xuanzong did so.

In 752, in the middle of a rebellion by the Tujue chieftain Li Xianzhong (李獻忠), the chancellor Li Linfu, who was then locked in a power struggle with fellow chancellor Chen Xilie and did not want to leave the capital Chang'an to react to the rebellion (as he was also the military governor of Shuofang), resigned his governorship of Shuofang and recommended An to take over for him. Emperor Xuanzong agreed, and made An the military governor of Shuofang.

Meanwhile, a rivalry had arisen between An Sishun and his cousin An Lushan, then the military governor of Fanyang Circuit (范陽, headquartered in modern Beijing) and the general Geshu Han, then the military governor of Longyou Circuit (隴右, headquartered in modern Haidong Prefecture, Qinghai). Emperor Xuanzong tried to foster better relations between them, and in winter 752 summoned all three to Chang'an. He had the powerful eunuch Gao Lishi hold a feast for the three of them, hoping that they would reconcile—but the feast degenerated into a bitter argument between Geshu and An Lushan, and it was said that instead of improving relations, it worsened their relations.

Death

At some point, An Sishun became aware that An Lushan, who also had a rivalry with chancellor Yang Guozhong, who had succeeded Li Linfu and was the cousin of Emperor Xuanzong's favorite concubine Consort Yang Yuhuan, was planning rebellion due to Yang Guozhong's aggravations. He reported it to Emperor Xuanzong, who did not believe it but nevertheless believed An Sishun to be faithful. After An Lushan did rebel early in 755, Emperor Xuanzong did not punish An Sishun, but recalled him to Chang'an to serve as the minister of census (戶部尚書, Hubu Shangshu). An Sishun's younger brother An Yuanzhen (安元貞) was made the minister of husbandry. An Sishun's subordinate Guo Ziyi was made the military governor of Shuofang.

However, Geshu Han was still inimical to An Sishun, and soon was put in command of the forces against An Lushan. In 756, Geshu forged a letter from An Lushan to An Sishun, and then had the messenger captured at a pass. He presented the letter to Emperor Xuanzong, along with a petition accusing An Sishun of seven crimes. As a result, An Sishun and An Yuanzhen were executed, and their families were exiled to the Lingnan region, despite Yang Guozhong's attempt to intercede on An Sishun's behalf.