Based on the self-developed by semiconductor refrigeration membrane distillation system, the energy consumption of the semiconductor refrigeration membrane distillation system was analyzed and calculated. Semiconductor refrigeration performance and membrane flux jump as the hydrothermal temperature in high temperature regional. But blindly increasing hydrothermal temperature will bring additional energy consumption system. Under the same hydrothermal temperature, the change trend of membrane flux and the system the change trend of tons of water energy consumption on the contrary. The tons of water energy consumption of system is almost linear growth，when the hydrothermal temperature is 75 ℃, the input current increases to 12A from 8A, energy consumption increment of basic remain at 8.5%. In order to determine the semiconductor refrigeration and membrane distillation system matching the optimal coupling condition, the two criteria is presented, the best matching condition and the best tons of water energy consumption standard. Contrast the two kinds of criteria and comparison,economic indicators are consistent.