The thermodynamic model of thermoelectric generatordriven thermoelectric cooler( TEG-TEC) device with Thomson effect is established. Performance of the device is analyzed by applying nonequilibrium thermodynamic theory and numerical calculation method.The influences of Thomson effect on the performance are analyzed by comparing the performance characteristics of models with and without Thomson effect. The results showed that,Thomson effect degrade the performance of TEG-TEC device, and the degradation of performance decreases with the increase of thermoelectric generator heat source temperature and cooling space temperature. Thomson effect decreases the cooling load by 29. 98%,decreases COP by 23. 02%,decreases limit cooling temperature by 11. 35% when hot junction temperature of TEG is 450 K, cold junction temperature of TEC is 285 K, and ratio of number of thermoelectric elements is 0. 5. In the design of the device,limited-number thermoelectric elements should be more allocated appropriately to TEG when consider Thomson effect. The results can provide some theoretical guidelines for the design of TEG-TEC devices.