Abstract: Nd:YAG/Cr4+:YAG bonding microchip laser crystal was used to develop a passively Q-switched high pulse energy narrow pulse all solid state laser. The pulse laser diode (LD) pump was used in this all solid state laser. The structure of oscillator and twice amplifications were designed. Besides, the self-excited oscillation and the restraining method were also analyzed. On the basis of stable oscillator laser output, the 1 064 nm output laser was obtained when the electric current of twice amplifications were 83 A and 85 A, respectively. The maximum single pulse output energy of the output laser was 120 mJ and the pulse width of the output laser was 1.28 ns. A green laser which the single pulse output energy was 65 mJ and the wavelength was 532 nm was obtained by the method of frequency doubling. The characters of narrow pulse and high beam quality can be used to provide a good pumping sources for the femtosecond lasers chirped pulse amplification.