In this work, hierarchical porous SnO₂/Zn₂SnO₄composites were synthesized via a facile one-step hydrothermal method with subsequent heat treatment. Many methods were performed to investigate the crystalline and morphological characterization of the as-prepared composite. The gas sensors based on the porous SnO₂/Zn₂SnO₄composite were fabricated and their gas sensing performance was systematically investigated. Significantly, compared with the pure SnO₂and Zn₂SnO₄solid particles, the hierarchical SnO₂/Zn₂SnO₄porous spheres exhibited excellent gas sensing properties toward triethylamine (TEA). The response value was 48 toward 100 ppm TEA, and the detection limit could be down to 500 ppb with a response value of 1.4. The excellent gas sensing properties are contributed to the porous nanostructure and the heterojunction between SnO₂and Zn₂SnO₄composite.