The invention provides a polarization controller The controller comprises two parts, namely a control unit and a vector modulating assembly, wherein the control unit is used for controlling the vectormodulating assembly through input control operation instruction data. The vector modulating assembly is used for dividing a signal which is input from a signal source into a horizontal-path signal and a vertical-path signal and performs amplitude and phase controlling on the two paths of signals. According to the polarization controller, configuration of a testing worktable is not required; a system does not require repeated detachment; high testing consistency is realized; and working efficiency is greatly improved.