A pulsed Nd:YAG laser with high average power is presented. The influence of offset angle of rods in six rods series connection resonator and the master oscillator power-amplifier (MOPA) system consisting of four rods oscillator and two rods amplifier are investigated theoretically. And the tolerances of offset angle are compared. It can be seen from the investigation results that MOPA system reduces the requirement of precision of series connection. With the same offset angle, the deviation of optical axis of the MOPA system is less than that of six rods resonator. It is helpful to improve the security performance of multi-rod pulsed laser, and obtain high average output power and high pulse energy. A MOPA system with four rods oscillator and two rods amplifier has been used in the experiment, and the offset angle of all rods is adjusted in the tolerance. With input electric power of 87 kW and a duty cycle of 17%, a maximum average output power of 3011 W, a peak power of 17.7 kW, a maximum single pulse energy of 67 J and a beam parameters product of 25.2 mm·mrad have been obtained. The electro-optical conversion efficiency is 3.46%, and instability of the laser is less than 2%.