The key issues to improve the performance of photocatalysts for selective oxidation of toluene are promoting the migration and separation of charge carrier, and enhancing the generation of active oxygen species. It is known that the construction of compact heterojunction is an efficient protocol to inhibit photogenerated electron-hole recombination. In this work, a 2D-2D [Bi₆O₆(OH)₃](NO₃)₃·1.5H₂O-Bi₂MoO₆ (denoted as BBN-BMO) composite heterojunction has been prepared by one-step hydrothermal method for the first time. The tetragonal phase BBN in the composite plays the role of transferring electrons from the visible light activated orthorhombic phase BMO and promoting the generation of active •O₂^-, the holes left in BMO are used to activate toluene and produce benzyl radical, thus greatly improving the photocatalytic performance for selective oxidation of toluene. The toluene conversion rate of BBN-BMO is 3466 μmol·g^-1·h^-1, which is three times that of pure BMO. The selectivity to benzaldehyde is 94.2%. In addition, reasonable mechanism has been speculated based on a series of control experiments.