Using the rubidium oxygen titanium phosphate (RTP) electro-optic deflector as a Q-switch, we realize a continuous wave LD-pumped Q-switched Nd:YVO4 laser and study the output characteristics in experiments at different output coupling rates and different repetition rates. An output pulse train of 1.22 W average output power with pulse width of 1.0 ns and peak power of 224 kW is obtained at the repetition rate of 5 kHz and an output coupler with transmittance of 60%. Another out pulse of 2.67 W average output power with pulse width of 2.2 ns and peak power of 60.7 kW is obtained when the repetition rate is 20 kHz, the slope efficiency is 37%, and the beam quality factors are M2x=1.226, M2y=1.229. Further, by extra-cavity double-frequency based on a potassium titanium oxide phosphate (KTP) crystal, a green laser at 532 nm with repetition rate of 20 kHz and average output power of 1.33 W is obtained, and the corresponding frequency-doubling efficiency is 50%.