[en] Highlights: • The calculated phonon frequencies and elastic coefficient indicated MgSnO₃ under compressive strain could meet stability. • The calculated band gap of R3c-MgSnO₃ under compressive strain by MBJ functional is agreement with the recent experiment. • The compressive strain can effectively regulate the stability, ferroelectricity and photoelectric properties of MgSnO₃. The stability, ferroelectricity, and electronic structure of R3c-MgSnO₃ and R3c-MgSnO₃ under compressive strain were investigated by density functional theory. The calculated phonon frequencies and elastic coefficient indicated that MgSnO₃ and MgSnO₃ under compressive strain could meet dynamic and mechanical stability. The phonon frequencies, elastic coefficient, and mechanical property have been increased in MgSnO₃ under compressive strain, which is explained by the bond length, Bader charge, and electronic structure. The bandgap of R3c-MgSnO₃ under compressive strain has been increased to 3.8 eV with an indirect bandgap to enhance optical transparency, which agrees with the experiment. The ferroelectric stability and polarization strength could also be promoted by the compressive strain in MgSnO₃. The stability, ferroelectric, mechanical, and photoelectric properties of R3c-MgSnO₃ could be controlled by compressive strain.