The invention discloses a redundant electronic steering system and control method of an autonomous vehicle. Two electronic power steering units are arranged, wherein each electronic power steering unit comprises a processor, a steering angle and torque sensor and a motor, wherein the steering angle and torque sensor and the motor are correspondingly connected with the processor; the steering angleand torque sensor is used for outputting a torque signal and an angle signal; the processor is also used for calculating a current total torque value K, needing to be output, of the whole system according to a current expected steering wheel steering angle signal, a torque signal and an angle signal and calculating a torque value needing to be output by the electronic power steering unit according to a distribution mechanism; and the processor is also used for controlling the motor correspondingly connected with the processor according to the torque value to control the vehicle to realize steering. According to the redundant electronic steering system and control method of the autonomous vehicle, full redundancy of the electronic steering system is realized, and safety requirements of automatic driving can be satisfied.