In order to realize the energy transfer from 1.06 μm laser to 1.57 μm human eye safe laser and retain the original 1.06 μm pump in the output beam,some key techniques of KTiOPO4 optical parametric oscillation(OPO) laser with repetitive frequency and dual wavelengths output have been analyzed theoretically and studied experimentally in detail.Intracavity optical parametric oscillator (IOPO) is adopted.Under repetition of 20 Hz,laser output energy of more than 38 mJ with dual wavelengths of 1.57 μm and 1.06 μm has been achieved.The laser output energy includes 20 mJ of 1.57 μm signal with 5 ns pulse duration and 18 mJ of 1.06 μm residual pump with 6 ns pulse duration.And,the waveform don't appear concavity.Results of the experiments agree with the theoretical analysis well.