The paper proposes a heat generation rate measurement method for large-size pouch lithium-ion batteries used in electric vehicles ( EV) , namely, the thermal compensation method. The curve relationship between the battery heat generation rate and operating current, temperature was studied, the effectiveness of the thermal compensation method was verified with the conventional method using heat flow meter. Finally, combining these two methods, the heat generation characteristics of the battery under high and low temperature rise conditions were studied. The study results show that the average calculated deviation of battery heat generation rate based on thermal compensation method is less than 5. 6% . The battery heat generation rate increases with the increase of operating current, and the relationship between the two shows quadratic nonlinear relationship. The heat generation rate of the battery under high temperature rise condition first decreases and then rises with the depth of discharge as a U-shaped curve. The average heat generation rate of the battery under low temperature rise condition is about 13. 7% higher than that under high temperature rise condition. The thermal compensation method proposed in this paper has the advantages of high accuracy, low cost, simplicity and flexibility. The research results can provide a guidance for the establishment of thermal model and thermal management system design of large-size pouch lithium-ion batteries.