Hydrogen energy replacing fossil fuel to calcine cement clinker is an effective way to save energy and reduce carbon emission in cement industry. Based on the theoretical calculation of thermal engineering, the theoretical combustion temperature and gas volume of different fuels such as hydrogen were analyzed, and a small suspension calcining test platform was built to simulate the combustion state of the calciner, and the feasibility of hydrogen energy replacing fossil fuels in calcining cement clinker was analyzed and verified. Results show that hydrogen has no additional theoretical gas volume compared to conventional fuel. Hydrogen-enriched combustion of coal or alternative fuels has a positive effect on reducing CO and NO_X in suspension calcination, thus promoting the utilization of inferior fuel. As a low-carbon fuel, Hydrogen can further play a high activity to solve the technical bottleneck of incomplete combustion and high NO_X background emission of alternative fuel in the calciner. According to the experimental results, for reducing fossil fuel consumption and carbon emission, the industrialization technical route of 20% hydrogen energy coupled with 60% alternative fuel is proposed to calcine cement clinker. Before this route is applied to practical projects, more in-depth pilot study is needed.