Based on the wave coupling theory of linear electrooptic effect in quasi-phase- matched periodical poled LiNbO3(PPLN), the control of the vector chaotic polarization of VCSEL output with external optical feedback by electro-optic modulation is numerically investigated. The investigation results show that the polarization state of VCSEL output switching periodically with the applied external electronic field or the length of the crystal. The original chaotic polarized state of its output caused by different parameters of VCSEL can be conversed into the other arbitrary chaotic polarized state. In particular, by controlling a certain applied external electronic field or the length of the crystal, any chaotic polarization model of VCSEL output can be conversed into two complete identical linear chaotic polarization model(x and ŷ polarization). In the case, this indicates that the energy of two linear chaotic polarization model can be steadily realized balanced status.