We investigate the structural phase transition and optical properties of RbSnX3(X = Cl, Br, I) at pressures of 0 and 160 GPa by means of the first-principles theory. Our calculated results indicate that two reconstructive phase transitions of P21/c(I) → ppPv-Pnma(IV) → P21/c(II) for RbSnCl3, ppPv-Pnma→ I4mm→ P21/c(III) for RbSnBr3, and ppPv-Pnma→ Pmn21→ ppPv-Pnma(IV) for RbSnI3are predicted. New ppPv-Pnma(IV) differed from other ppPv-Pnmaphases in previous reports [Phys. Rev. B2018, 97, 020103(R)], and diversified P21/cphases are obtained. More importantly, RbSnBr3and RbSnI3systems present an obvious piezochromic effect and a semiconductor-to-metal phase transition. Furthermore, the pressure-induced optical and mechanical properties of these stable phases are investigated and analyzed comprehensively. Meanwhile, a superconducting critical temperature Tcof 1.2 K at a pressure of 140 GPa of the metal phase ppPv-Pnma(IV) in RbSnI3is also estimated. These results provide comprehensive theoretical guidance and support for enriching the high-pressure phase diagram and diversified properties of halide perovskites under high pressure.