Abstract: High-strength and plasticity Mg-Sn-Zn-Zr (TZK) alloy was prepared by gas shielding method, and then the alloy was subjected to extrusion deformation at different temperatures (300 ℃, 350 ℃and 400 ℃), and the microstructure, phase composition and in-vitro degradation behavior of the alloy were studied.The results show that the microstructure of the alloy after extrusion at 300 ℃is uniform and fine equiaxed grains, and the grain size is the smallest, which is 6.57 μm; the hydrogen evolution and corrosion rate are lowest, and the corrosion resistance is best.With the increase of extrusion temperature, the grains of the alloy grow up and twin crystals appear in the structure, resulting in poor corrosion resistance.