<p>This study systemmatically investigated the effects of solid content and dispersant content on the physicochemical properties of ZnO-SnO₂ composite ink. The experimental results show that even with the use of low-molecular-weight PEG400 dispersant, gas-sensitive ink with high solid content and good suspension stability can be obtained, which is advantageous for low-temperature film formation and can effectively prevent property changes and film crack of high-temperature-sintering-induced material. Under this condition, the ink at a 15wt% solid content and 2wt%–10wt% PEG400 has good film-forming ability and high adhesion strength on the micro-electromechanical system (MEMS) micro-hotplates. Especially, the MEMS sensor printed using the ink of 6wt% PEG400 shows highest sensitivity, favorable impact resistance, thermal shock resistance, and up to 8 years of service life.</p>