Chiral perovskites have attracted tremendous attention to motivate the development of chiroptoelectronics, but the structural configuration supporting efficient spin-polarized emission (SPE) and optical gain has yet to be comprehensively explored. Herein, we uncover the intrinsic ground-state and excited-state chirality in chiral 1D perovskite crystals, study excited-state chirality in mixed-halide films with suppressed signal crosstalk, and achieve and enhance chirality-triggered SPE in three dimensions (3D) embedded in one-dimensional (1D) (3D@1D) perovskites toward displays. SPE in 3D@1D perovskites was modulated by varying the 1D-to-3D molar ratios, leading to a record efficiency of 89.04% for chirality-induced optical spin polarization. It was further enhanced by stimulated emission, reducing operation temperature, and altering halide composition, resulting in a significantly boosted glum of 29.2%. These results provide an in-depth understanding of chirality-triggered SPE in high-performance optoelectronics.