We prepared CsPbBr3/ZnO heterojunctions by self-assembling colloidal CsPbBr3 quantum dots (QDs) on the surface of the ZnO film. The fluorescence of CsPbBr3/ZnO heterojunctions was modulated by titanium nitride nanoparticles (TiN NPs) to obtain highly photoluminescent CsPbBr3/TiN/ ZnO heterojunctions. The results showed that when the TiN thickness was 51 nm, the fluorescence of the CsPbBr3/TiN/ZnO heterojunction was enhanced by 3.2 times compared to that of the CsPbBr3/ZnO heterojunction. TiN NPs combined most of the photo-generated electrons with the holes on the surface of the TiN/CsPbBr3heterojunction, which increased the electron transfer rate and reduced non-radiative recombination. This method of enhancing heterojunction fluorescence could provide a new pathway for photovoltaic, light-emitting diode (LED), photodetector, light sensor, and image sensor applications.