A multifunctional electric recirculating ball steering system for commercial vehicles and its control method are described. The system comprises three modules: an electric power module, a mechanical transmission module, and a control module. The system introduces a dual-rotor motor and a common power motor, working together to act on the input end of a recirculating ball steering gear. The dual-rotor motor offers high redundancy, increased output torque, and improved reliability for control-by-wire operations. A fork assembly enables synchronous and asynchronous rotation of the dual rotors, achieving both steer-by-wire and electric power steering functions. Leveraging the high reduction ratio capability of the recirculating ball steering gear maximizes power torque and simplifies the system architecture while ensuring reliability in both traditional control and control-by-wire functionalities.