<p>In this study, the influence of solution treatment on the microstructure and mechanical property of extruded WE43-0.5Ca magnesium alloy was explored. The microstructure was analyzed using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). Mechanical properties were analyzed using a universal testing machine. The results revealed that the microstructure of WE43-0.5Ca magnesium alloy is composed of <i>α</i>-Mg matrix, Mg₂₄Y₅ phase, Mg₄₁Nd₅ phase, and Mg₂Ca phase. The majority of the second phase particles are distributed along the grain boundaries, with a small amount dispersed within the grains. After solution treatment, the number of second phases in the microstructure is reduced. When the solution treatment is at 490&#xa0;°C for 12 h, the morphology of the second phase transformed from a chain-like structure to discrete single grains. Moreover, abundant nanoscale precipitated phases were precipitated within the grains, and the maximum extreme density value was the largest, and the texture distribution was relatively concentrated under this condition, and the comprehensive mechanical properties are the best. This indicates that the maximization of balance is achieved under the four strengthening mechanisms of fine-grain strengthening, second phase strengthening, solid solution strengthening, and precipitation strengthening.</p>