The energy consumption of electric vehicle (EV) is affected by many factors. In order to reveal the influence of driving style on the energy consumption of EV, the energy consumption experiment of the whole vehicle was designed by controlling the univariate factor. Through the combination of experimental test and theoretical calculation, the energy distribution of each component was obtained, and the energy consumption was quantitatively analyzed to highlight the direction for optimizing the energy consumption of EV. Firstly, the energy flow of EV under the condition of constant speed was analyzed, identifying the influence of certain factors on the vehicle energy consumption. Then the influence of driving style on the energy consumption of EV was analyzed under the comprehensive working conditions. The results show that the battery energy was mainly consumed by the electric motor control system and vehicle driving resistance, and the energy consumption of accessories was very little. The driving style mainly causes the fluctuation of energy consumption by affecting the braking loss and the operating efficiency of power transmission system. Different driving styles will lead to a difference of more than 10 kW·h in the energy consumption per 100 km.