For the mode-selection and wavelength control of rare-earth crystal infrared lasers, two-sided mirror resonator based on grating-coupling is proposed in this paper. The single laser mode output and wavelength control of yttrium-scandium-gallium-garnet (Er∶YSGG) crystals are realized by utilizing the high reflectivity, frequency selectivity and angle tuning properties of the periodic surface of the grating. The experimental results show that when the grating angle varies from 21.1°-21.6°, the Er∶YSGG laser exhibited single-mode operation, and its wavelength is switched from 2796.8 nm to 2824.4 nm. The obtained laser output power is 4.3 mW. The grating two-sided mirror cavity provides a simple and effective technical solution for the single-mode output of the rare-earth crystal infrared laser.