A diode-end-pumped AO Q-switched YVO4/Nd:YVO4 composite crystal laser is demonstrated in this paper. With a comparative simple cavity, the laser can generate short pulse duration and high peak power by optimum design. The shortest pulse width of 9.5 ns and the maximum average output power of 10.12 W are obtained at the repetition rate of 90 kHz, corresponding to an optical conversion efficiency of 37.5%. A 4.2-ns pulse with 2.9-mJ pulse energy and 691.4-kW peak power has been achieved under 20 W incident pump power at 1 kHz.