Petal bismuth salt semiconductors are promising as visible-light-driven photocatalysts, but their short service times due to strong oxidation limit their application. In this research, the in situ construction of a p-n heterojunction, by growing BiOX on a KBiO3 surface, is used as a strategy to improve the performance and stability. Evaluation of the photocatalytic degradation of crystal violet and phenol shows that the KBiO3/BiOX (X = Cl, Br, I) heterostructures exhibit significant improvement in photocatalytic performance and stability compared to KBiO3. The best one, KBiO3/(5.85%) BiOI, shows 98% degradation of crystal violet within 20 min, and of phenol within 1.5 h. No significant performance decay can be detected after repeated use. The development of KBiO3/BiOX heterostructure improves the applicability of KBiO3 as an efficient visible-lightdriven photocatalyst.