In this paper a future improvement was made based on continuous flow method. The algorithm is faster and more accurate when used to analysis the static voltage stability of power systems. PQ decoupled power flow algorithm is used, Lagrange quadric interpolation is used to predict the next initial value in the process of predictor and an improved parameterized method based on the principles of geometric similarity is used in the corrector. Compared with conventional continuation power flow, the improved algorithm has advantages in terms of computation speed, less memory requirement and accuracy. Sample studies show that the algorithm has the advantages of feasibility, high-speed and high accuracy.