Abstract: Considering the specific requirement of reliability of military lasers, a consolidated intracavity eye safe optical parametric oscillator (OPO) is designed. By using double directional prism resonator,Cr4+:YAG passive Q-switch, Ce Nd:YAG laser rod, noncritical phase matching KTP crystal,1.57μm OPO laser is obtained with 5.3mJ/pulse of energy,≈6 ns of pulse width and ≈5mrad of divergence. After continuously working for 1min at the repetition rate of 3Hz, the output energy and optical axis is still stable. It had the characteristics of compact structure and high reliability.