A multi-wavelength LD pumped square rod-shaped Nd∶YAG temperature-free solid-state laser is reported in this paper.The laser adopts LD side pumping mode,and the LD pumping module is composed of four LDs with different center wavelengths.At 25 ℃,the center wavelength of each bar is 802nm,804nm,806nm,808nm,and the full width at half maximum of the LD module is about 7 nm.The working medium is a side double-sided square rod-shaped Nd∶YAG bonded crystal,and the effective absorption length of the working medium can be increased by controlling the optical path;the Q-switching mode is electro-optic Q-switching;and a temperature-free solid-state laser is obtained.The laser can be temperature-free and stable output energy≥40 mJ in the temperature range of -40~+60℃.The horizontal divergence angle of the output laser is 1.79 mrad,and the vertical divergence angle is 1.36 mrad,the beam quality:M2x=4.858,M2y=2.697.