Abstract: Disclosed is a semi-passive resistance force control system with active augmentation, which is suitable for a sport equipment with a pulling part. This semi-passive resistance force control system with active augmentation comprises a resistance force module, an energy neutral apparatus, and a control module. The energy neutral apparatus can not only provide an output resistance force to the pulling part when the pulling part is pulled by a user, but also reduce the variation of the output resistance force. The control module is able to accept the sensing data delivered by the internal sensors of the semi-passive resistance force control system with active augmentation to passively compensate the output resistance force and make it fixed. Furthermore, the control module can also provide an active adjustment to the output resistance force based on a preset control mode such that the user can experience a desired resistance force.