The flow field of the heat dissipation system of nickel-hydrogen(Ni-MH) battery package used in hybrid electric vehicle(HEV) is simulated with Fluent software. The steady-state simulation analysis on the temperature field of the Ni-MH battery package is carried out based on the air flux in the battery packages. The sensors arrangement scheme for the temperature field measurement experiment is decided based on the temperature field simulation result. The experiment of the temperature field measurement is performed under the condition of the driving cycle of the HEV. Then the transient temperature field of the battery package is analyzed based on the unit volume thermal power，which is calculated from the current data got from the experiment. The result shows that the simulation results mach well with the experimental data，and the heat dissipation system of the battery package function well for heat dissipation，which satisfies the demand of the HEV on the battery package.