A kind of electro-optic Q-switched laser in the form of pulse group output with short pulse interval and high subpulse peak power is proposed. The Nd∶YAG crystal is pumped by the diode laser (LD) module, and the single energy storage of resonant cavity is achieved. On the basis of controlling the Q-switch steps open repeatedly, single pump energy can be divided into multiple times Q-switched outputs and the short pulse interval and pulse group laser output are obtained, providing a research way for high repetition frequency and high peak power laser. Results show that with a group of half ring laser diode module as the source for Nd∶YAG crystal, lithium niobate (LN) crystal as the Q-switch, storage material is single pumped by laser diode module, and the Q-switch is stepped opened, the laser can be stably operation in the range of 1-20 Hz, minimum subpulse interval of 100 ns is obtained and subpulse frequency ranges in 1.1-10.0 MHz, subpulse energy is greater than 23 mJ and energy fluctuation is less than 10%, single pulse width is less than 37 ns, subpulse peak power is close to 1 MW, and the optical-optical conversion efficiency is 22.5%.