To acquire small volume and high power mid-IR laser，1.06 μm high power and high beam quality fiber laser output is obtained by using high repetition frequency driving Q-switched synchronization technology and seed injection magnify technology.The outputs of two beam laser are obtained in exterior polarizer,and plates polarized optical principle is adopted to acquire laser outputs of two beam polarizer identity,PPLN is pumped to obtain high power 3~5 μm Mid-IR laser output.As the input current is 60 A and the Q-switched frequency is 50 kHz ，the max power of 3.8 μm laser output is 6.2W,1.06 μm to 3.8 μm conversion efficiency is 16%.Experiment results indicate that fiber laser pumped optical parametric oscillator can be used to obtain 3.8 μm high power Mid-IR laser output.