A high power mid infrared (Mid-IR) laser is introduced. High frequency laser of 2.05 μm is obtained in Ho:YLF laser pumped by 1.94 μm laser, and the power of 2.05 μm laser is increased by amplifying in an endpumping schedule, finally, a high power Mid- IR laser is obtained in a OPO pumped by the 2.05 μm laser. The schedule is cooled by water,the max power of Mid- IR laser is up to 26.9 W, the pulse width is 24.4 ns, the efficiency from 2.05 μm to Mid- IR is up to 50% , and the wavelength is varied with the different input angle. Through the experience, it is proved that a high power, high frequency and high efficiency Mid-IR laser can be realized in this method.