Abstract: Based on the excellent cooling characteristics of CO₂ as a natural working substance and development prospects in the field of many hydrate technology, using the characteristics of pressure rising sharply under the phase equilibrium transition temperature of hydrate, through the innovation design of process, the carbon dioxide hydrate formation and decomposition alternate process is used to realize the pressurization system. Based on thermodynamic analysis of carbon dioxide level cascade refrigeration and combining with the phase equilibrium temperature, the experiment results show that the dynamics of 0.3wt% SDS additives is more advantageous to promote the formation of carbon dioxide hydrate in double-tube reactor compare with 4wt% THF thermodynamics additive. The synthesis time is 60 minutes at 1.4 MPa and -2℃. In SDS solution of 0.3wt%, lower temperature is more beneficial to the formation of hydrate, the critical temperature is close to -2℃. When it is lower than -2℃, the solution icing may block pipe. When the two sets of tube reactors are used alternately, the optimum cyclic temperature is as follows:the synthesis temperature is -2℃, the decomposition temperature is 10℃, and the shortest cycle time is 55 minutes. The carbon dioxide gas under high pressure is decomposed by condensation throttle to a low temperature of -36℃.