Embodiments of this application disclose a pull drift compensation assist system and a control method. The control method includes: determining status information of differential drive assist steering; and when differential drive assist steering works, performing pull drift compensation through differential drive assist steering; or when differential drive assist steering fails, performing pull drift compensation through electric power steering. The assist system includes a control module, a main compensation module, and an auxiliary compensation module that communicate with each other. In the technical solutions provided in embodiments of this application, compensation can be performed through differential drive assist steering, to effectively reduce occurrence of a long-time motor blocking phenomenon, reduce a motor fault risk, and reduce a motor performance deterioration degree. Compensation through differential drive assist steering may expand a hand force compensation range. Main/auxiliary system redundancy backup of differential drive assist steering and electric power steering may reduce a failure probability of pull drift compensation, and improve running safety of a vehicle. Long-term compensation and short-term compensation are performed concurrently, so that compensation for both deviation caused by an external factor and deviation caused by a factor of the vehicle may be implemented.