Low-dimensional metal halide hybrids with efficient warm white-light emission from self-trapped excitons (STEs) have attracted extensive attention for interior lighting because of their fascinating emission features including high colour rendition, excellent colour stability, and low manufacturing cost. Despite great efforts, the mechanism of STEs in one-dimensional (1D) metal halide hybrids is still unclear, which makes the way to regulate white-light emission is still worth exploring. Here, we prepared a double-chain organic-inorganic metal halide hybrid crystal, (C6H18N2)Pb2Br6∙H2O (DEPBH). Strikingly, DEPBH shows a warm white-light emission with an appropriate correlated colour temperature of 3714 K and high colour rendering index up to 89. Especially, further research reveals that STEs springs from the 1D core-shell quantum-wire frame play a crucial role in such warm white-light emission of DEPBH. This work offers a new route to fabricate single-component warm white-light phosphors in low-dimensional materials and will contribute to the further exploration of their relationships between crystal structure and optical properties.