Thermodynamic method is currently recognized as one of the feasible exploitation methods for natural gas hydrate.How to improve the utilization ratio of injected energy in the thermal recovery process so as to maximize the ratio of the total calorific value of methane gas, the injected calorific value is mostly focused on the analysis of the optimal injection temperature.From the point of view of obtaining the maximum gas production rate, on the basis of energy utilization rate, this paper defines a new thermal efficiency as the energy utilization rate of hydrate heat injection under the unit gas production rate.Based on the concept of infinite cylindrical heat transfer reactor, a new one-dimensional transient heat transfer model under isothermal boundary conditions is established.By deriving the analytical expressions of heat transfer quantity and time in the process of inter-wall heat transfer, the thermal efficiency of inter-wall heat transfer for hydrate extraction is found to be between 0.431 and 0.536 at the mining temperature of 20~100℃. The optimum injection temperature is 65℃and the thermal efficiency is 0.536.