Abstract: The 2 μm laser with low repetition rate, high peak power and high beam quality has a wide application prospect for nonlinear frequency transformation of mid-infrared and long-infrared optical parameters. The Ho: YLF crystal is pumped by a 42W Tm doped fiber laser with an L-shaped resonator structure. Laser output with wavelength of 2.05 μm, repetition rate of 50 Hz, pulse width of 18 ns , pulse energy of 13.5 mJ, and peak power of 0.75 MW is realized based on the electro-optic Q-switching technology of rubidium titanate phosphate (RTP). And the beam quality M² factors in the horizontal and vertical directions are 1.4 and 1.1, respectively. The Ho: YLF solid state laser is pumped by a fiber laser and has a compact structure, and it will build the foundation for Ho laser with higher pulse energy.