An electric vehicle and a power system and a motor controller for an electric vehicle are provided. The power system includes a power battery; a charging-discharging socket; a bidirectional DC/DC module connected with the power battery; a driving control switch connected with the power battery and the bidirectional DC/DC module; a bidirectional DC/AC module connected with the driving control switch and the power battery; a motor control switch connected with the bidirectional DC/AC module and a motor; a charging-discharging control module connected with the bidirectional DC/AC module and the charging-discharging socket; and a controller module connected with and configured to control the driving control switch, the motor control switch and the charging-discharging control module according to a current operation mode of the power system.