A work machine control system that controls a work machine including a working device having a working tool that rotates about a shaft line includes: a target construction shape generation unit that generates a target construction shape indicating a target shape of a construction target of the work machine; a target shape calculation unit that calculates a control target shape which is a target shape when controlling rotation of the working tool from the target construction shape and calculates an extended target shape obtained by extending the control target shape; and a working device control unit that controls the rotation of the working tool about the shaft line based on a distance between the working tool and the control target shape and the extended target shape.