An undoped YVO4 crystal is employed to achieve efficient stimulated Raman scattering conversion in a diode-pumped actively Q-switched Nd:YAG laser. With an incident pump power of 16.2 W, an 1176 nm first Stokes average output power of 3.0 W was generated at a pulse repetition rate of 50 kHz, corresponding to an optical-to-optical conversion efficiency of 18.3%. Moreover, the maximum optical-to-optical conversion efficiency of 21.3% was found at 20kHz. The maximum pulse energy is higher than 83 μJ at both 20 and 30 kHz. With an incident pump power of 7.6 W, the underestimated peak power of 43.5 kW was demonstrated at 20 kHz with mode-locked modulation.