OBJECTIVE： To shorten the time of admixture of temporary medical order in PIVAS， and to guarantee the timely treatment of patients. METHODS： Through the definition， measurement， analysis， improvement and control ie. five steps of six sigma method， the consumed time of each link of temporary medical order admixture in PIVAS was analyzed in our hospital during Mar. 9th-22nd in 2015 （before improvement）； key points were found out， and relevant measures were formulated and improved； the consumed time of each link of temporary medical order admixture in PIVAS was collected again during Jul. 27th-Aug. 9th in 2015 in order to evaluate improvement effects. RESULTS： It was quality key point that total length of temporary medical order admixture which included injection sequence， label checking， preparation， package rechecking， drug distribution and so on， was controlled within 120 min； through formulating and implementing various measures as improving information system， adjusting preparation sequence and shunting staff posts flexibly， the total time of first 3 batches of temporary order admixture were 120， 98 and 77 min after improvement， shortening by about 30， 50 and 55 min respectively， compared with before improvement （P＜0.05）. CONCLUSIONS： The six sigma method has shortened the time of temporary order medical admixture in our hospital. The formulated measures are effective and feasible.