The pulse output of intracavity optical parametric oscillator(OPO) is achieved by designing the proper cavity structure of OPO.1.064 μm fundamental light with high beam quality.By using electro-optic Q-switch and flash lamp pumping Nd∶YAG crystal.1.57 μm eye-safety laser is achieved by motivating Π-class noncritical phase matching KTP crystal with the fundamental light.The output waveform and output energy of OPO are measured.The output energies of OPO are measured under different mirror radiuses of curvature.The relationship between pump voltage and output energy is obtained.The maximum optical-optical conversion efficiency of 14.2% is gotten when the radius of reflector is 8 meters,which is consistent with the experimental results of software simulation.