An efficient mid-wave infrared gain-switched Cr2+ :ZnSe laser pumped by a 2.058μm Tm,Ho:YVO4 laser is reported.As much as 3.86 W output is achieved with the pump power of 13.4 W at puke repetition frequency of 15 kHz,corresponding to the slope efficiency of 30.9%.With a quartz birefringent filter inserted in the laser cavity and by rotating the exteal angle of the quartz birefringent filter,wavelength tuning range nearly from 2453nm to 2508nm with 5nm linewidth(FWHM) is also obtained.