With the proposal of the "dual carbon" goal, China's new energy construction is in a new stage of development. However, the randomness and volatility of high permeability new energy also pose challenges to the static voltage stability analysis of the power system. At the same time, the development of power electronics technology has led to the widespread application of flexible AC transmission system (FACTS) in regulating power flow and improving static voltage stability of power systems. A probability assessment method is proposed for static voltage stability of power systems with distributed static series compensator (DSSC) considering the uncertainty of new energy sources. Firstly, the static voltage stability mechanism of the new energy grid connected system is analyzed. Then, the working principle of DSSC is explained, an equivalent power injection model of DSSC is established, and based on this model, the power flow equation containing DSSC is derived. Secondly, based on the power flow calculation equation, a static voltage stability index that can map the uncertainty of new energy sources is proposed, and the Monte Carlo simulation method is used to realize the probability assessment of the static voltage stability index of the system. Finally, through case analysis, it is verified that the uncertainty of high permeability new energy leads to a larger distribution range of static voltage stability indicators in the system and an increase in the probability of system instability. Reasonable configuration of DSSC can effectively improve the static voltage stability of power systems. The proposed method can accurately reflect the impact of new energy uncertainty on the stability of the power grid, and has certain engineering application value.