In traditional Open Circuit Voltage (OCV) model modeling method, the OCV curve is fitted by the least squares method, so that the OCV test point cannot fall on the curve and the modeling precision is low. For this reason the use of Hermite interpolation method to establish the battery OCV model. Firstly, interval discharge of the battery is implemented to obtain several OCV test points. Then, piecewise cubic Hermite interpolation function is used to establish OCV model and the OCV curve is fitted. Finally, verify the validity of the established OCV model. Verify the experiment through the battery at different temperatures under the UDDS dynamic discharge test, and the OCV curve is applied to the SOC estimation of the EKF algorithm to verify the accuracy of the OCV model by comparing the SOC estimation results. The experimental results show that the Hermite interpolation OCV model is feasible at different temperatures. Compared with the traditional OCV model, the Hermite interpolation OCV model has higher modeling accuracy.