A polarization controller composed of four electro-optic crystal plates which phase delay can vary from 0 to 2π is proposed, and simulated annealing algorithm is taken on as feedback control in this controller. Simulated research shows that this controller is endless and the output polarization state is stabile while the light intensity fluctuates less than 1%. The research on control parameters indicates that the initial temperature about 0.1 and the temperature transforming function T_ k+1 =0.2T_k are required for this controller. The state generating constant s sharply influences the convergence and its better range is between 0.005 and 0.01. To reduce running time, the repeat number 9 is introduced for once search.