[Problem] To provide a control method of a work vehicle, a work vehicle control program, a work vehicle control system, and a work system, by which appropriate determination of an override state becomes possible.
[Solution] A control method of a work vehicle 10 is a control method of a work vehicle 10 having an automatic steering mode for automatically steering a steered wheel using a motor 421. The control method includes: in the automatic steering mode, controlling the motor 421; determining whether the work vehicle 10 is in an override state on the basis of a determination condition related to torque generated in the motor 421; and changing the determination condition.