Laser diode (LD) end-pumped, thermally bonded Nd:YAG/Cr4+YAG passively Q-switched laser is theoretically analysed and experimentally studied. The key laser parameters such as repetition rates, pulse width, peak power, pulse energy and mutual relation are investigated. The high peak power of 6.25 kW, pulse energy of 50 μJ, pulse width of 8 ns, repetition rate of 200 kHz laser are obtained. Experiment shows that thermally bonded solid state laser has high repetition rate, short pulse widh and high peak power.