A laser diode pumped Nd∶YAG/Nd∶YVO4/Cr∶YAG passively Q-switched laser is reported. Compared with Nd∶YAG/Cr∶YAG laser, the polarization ratio is improved in this configuration, the higher conversion efficiency is achieved in optics nonlinear frequency conversion, an output power of 2.8 W at 1064 nm with repetition rate of 15 kHz and pulse width of 7 ns is achieved and the polarization ratio of the laser is more than 80∶1. 223 mW output power at 355 nm is obtained using two LBO crystals as optics nonlinear frequency conversion crystal.