The focus of this work is to develop a sensitive and reliable acetone gas sensor using the Pt-modified Co3O4/CoMoO4 heterojunction derived from metal-organic frameworks (MOFs). Pt-loaded Co3O4/CoMoO4 heterojunction was successfully prepared by the surface redox method, and the composites exhibited high sensitivity and selectivity for acetone with a low detection limit. By modifying the Co3O4/CoMoO4 material with platinum loading, the sensor achieved a response of 24.12 to 20 ppm acetone, which was significantly better than that of the pure Co3O4/CoMoO4 heterojunction. This work not only improves acetone detection strategies, but also enhances the potential for industrial and medical VOC monitoring applications.