Lots of small hydropower stations gather in the west of Yunnan province, where are far from Yunnan main power grid in electric distance, and therefore dynamic stability in this area is serious. Based on the disturbed temporal trajectory dynamic performance index and cost of investment, SVC, STATCOM and TCSC single FACTS element integrated optimization model is established respectively in order to improve the dynamic stability and transmission ability. And an improved difference evolution algorithm is applied for the different types of single FACTS element configuration parameter and capacity. The result shows that STATCOM is the best single FACTS element to improve dynamic stability Western Yunnan power grid.