The invention discloses a power supply control method and system of a central control system of an electric vehicle. The method comprises the steps that according to working states of the central control system of the electric vehicle under different application scenes, multiple power supply mode states are set correspondingly; voltage values of a storage battery of the electric vehicle and operation events of the electric vehicle are detected, and according to preset state switching conditions and priority levels, switching among different power supply mode states is achieved; according to the power supply mode states, the central control system is subjected to corresponding power supply control. The power supply control method and system of the central control system of the electric vehicle can achieve power supply optimization control on the central control system, shorten the starting time, achieve power supply optimization, meet the operation experience of users, are high in intelligent degree, and can be widely applied to control systems of electric vehicles.