One of the major challenges in photocatalytic hydrogen production is to improve the separation efficiency of photo-generated carriers. Therefore, we prepared ZIS/BMO heterojunctions by hydrothermal method to promote the directional separation of photogenerated carriers. A series of characterization results show that the successful preparation of heterojunctions substantially increases the separation and transfer rate of photogenerated carriers. 11% ZIS/BMO had the highest photocatalytic hydrogen production performance reached 1502.6 μmol/g/h, which is 2.78 times than ZIS monomer. Simple construction of heterojunctions but dramatic improvement of photocatalytic hydrogen production performance opens up new horizons for photocatalyst modification.