Hybrid 1D nanomaterials with hierarchical structure have received a great deal of attention as sensing materials for gas sensors due to their high surface area, excellent catalytic performance, and robust structure. Novel Zn2SnO4 nanorod‐decorated Mn3O4nanowire 1D nanostructures are prepared by a two‐step hydrothermal method and subsequent heat treatment for application in gas sensors. The branch‐like Mn3O4/Zn2SnO4 composite‐based sensor exhibits high sensitivity and excellent selectivity for the detection of acetone gas. Importantly, the sensitivity of acetone‐gas sensor can be improved by optimizing the content of Zn2SnO4 nanorods on the surface of Mn3O4nanowires. As a result, such a 1D–1D branch‐like Mn3O4/Zn2SnO4 hierarchical structure with effective p–n heterojunction and large specific surface area would display excellent electron transport property, which determines if the material is capable of recognizing target gases, thus enabling the sensor to achieve high sensitivity.