Broadband emission of two-dimensional perovskite has aroused interest in single-component white-light-emitting diodes. In this paper, we use the soft lattice properties of two-dimensional perovskite (PEA)₂PbBr₂Cl₂ and (C₆H₁₈N₂O₂)PbBr₄, which have strong photoacoustic coupling effect. The photo-excited electron-hole pair (exciton) is easy to cause lattice distortion and thus be captured by the lattice, forming self-trapping excitons (STEs), which can emit full spectrum white light. The results show that the half-height and full width of the two materials can reach 232 nm and 194 nm, the stokes shift is 182 nm and 198 nm respectively, and the fluorescence lifetime is 9.812 ns and 13.465 ns. Their coordinates on chrominance diagrams (CIE) are (0.36, 0.40) and (0.40, 0.44), color rendering indexes (CRI) are 86.93 and 82.23. Based on these two kinds of perovskites, combined with commercial UV LED, the composite LED color temperature is about 5000 K, providing a new understanding and perspective for the design of single-component white-light-emitting diodes.