An experimental set-up was designed for measuring the To investigate the impact of secondary phases on the microstructure and mechanical properties of Mg-Sn-Zn-Ca alloys, this study employed both isothermal and incremental temperature rolling processes on Mg-2Sn-2Zn-1Ca magnesium alloy sheets. Subsequently, mechanical property assessments, microstructural analyses, and fracture surface elemental examinations were conducted on both sets of samples. The results indicate that under isothermal rolling conditions, the sheets exhibited lower yield strength and inferior ductility compared to the as-cast condition. In contrast, the specimens treated with incremental temperature rolling demonstrated superior formability, yield strength, and ductility. This disparity can primarily be attributed to the effective modulation of secondary phases. During isothermal rolling, an increase in the content of secondary phases (MgxZny) led to larger particle sizes, which induced stress concentrations, thereby contributing to premature material failure. Conversely, incremental temperature rolling facilitated interactions between secondary phases and high-density dislocation regions, acting as preferential nucleation sites during recrystallization, thereby enhancing the material""s plasticity. This study underscores the importance of incremental temperature rolling technology in modulating the secondary phases of magnesium alloys and demonstrates its potential in improving the formability and overall performance of sheet materials. It provides a novel perspective on the optimization of the microstructure of magnesium alloys.