1D chiral perovskites, exhibiting anisotropic and chiroptical activities, are highly promising candidates for full-Stokes polarization detection. However, inefficient chirality transfer in these materials results in weak chiroptical responses, seriously limiting their capability for circular polarization discrimination. Here, we develop a facile Sb3⁺ doping strategy to effectively modulate the structural asymmetry of (R/S-3AD)PbBr3Cl·H2O crystals (3AD = 3-aminopiperidine dihydrochloride), significantly enhancing the chirality transfer from chiral organic components to inorganic framework owing to the symmetry-breaking lattice distortions and yielding a 30-fold increase in chiroptical activity. Furthermore, the doped chiral perovskite crystals exhibit a pronounced Dember effect, enabling self-driven photodetection. As a result, the Sb3⁺-doped (R/S-3AD)PbBr3Cl·H2O crystals achieve a maximum circular polarization sensitivity factor of 0.44 and a linear polarization ratio of 1.43 at zero bias, allowing accurate full-Stokes polarization detection with a Stokes parameter averaging error below 7%. This study offers a new strategy for boosting the chiroptical responses in chiral perovskites and presents the first demonstration of self-driven full-Stokes photodetection via the Dember effect.