A nanosecond Nd:YAG-based double-pass amplifier system has been developed by experiment.The output single pulse energy of the master oscillator is 0.16 mJ at repetition frequency of 5 Hz,the beam quality of M2 is 1.5,and the pulse width is 0.964 ns.After amplified by Nd:YAG-based double-pass amplifier with size of 3 mm×120 mm and doping concentration of 1.0 at.%,the total single pulse energy is 88 mJ,pulse width is 0.975 ns,M2 is 1.7,and the stability is within ±3%.