Abstract: The effects of solution temperature on the microstructure and corrosion properties of Mg-3Zn-1Mn-1Y alloy were studied by OM, XRD, immersion method and electrochemical workstation. The results show that after solution treatment, the second phase in the alloy gradually dissolves into the matrix and grows with the grouth of the grain growth.With the increase of solution temperature (390 ℃, 420 ℃, 450 ℃, 480 ℃), the corrosion resistance of the alloy first increases and then decreases.At 450 ℃×24 h, the alloy shows the best corrosion resistance, and its corrosion rate is (0.4127±0.024)mm/y.The reason for improving the corrosion resistance of the alloy is that the microstructure is uniform after solid solution and the dissolution of the second phase leads to the weakening of micro galvanic corrosion.