The invention discloses an electric water heater control system capable of being powered off intelligently. The electric water heater control system comprises a three-pole leakage protection plug power cord, a single chip, an electric heater, a first relay, a second relay, an isolating communication module, a chargeable and dischargeable power supply module, a power detection module and a hardware power-on resetting module, wherein the three-pole leakage protection plug power cord can be reset automatically; the isolating communication module is used for realizing strong electricity and weak electricity isolation and communication. When the electric water heater control system is in work, the isolating communication module can be triggered by a remote controller, a machine body key or a remote control terminal which is connected with the single chip, so that the isolating communication module is capable of transmitting a power-off signal or a power-on signal in order to realize disconnection and connection of the three poles (a zero wire, a fire wire and a ground wire) of the three-pole leakage protection plug power cord, so a user can easily operate the leakage protection plug power cord which is mounted at a high position, safe bathing of the user is guaranteed, and the operation is convenient.