Abstract: Due to the poor performance of existing methods in the automatic control of differential steering for indoor unmanned vehicles, which not only results in a significant deviation between the positional response and the desired position but also leads to a relatively high overshoot in differential steering and a long response time, failing to achieve the expected control effect, an automatic control method for indoor unmanned vehicle differential steering based on sliding mode variable structure is proposed. Firstly, based on the characteristics of the differential steering system, a dynamic model for the unmanned vehicle's differential steering is established. Secondly, the front wheel steering angle of the unmanned vehicle in the dynamic model is taken as the control variable. Finally, using the sliding mode variable structure theory, the sliding mode surface and reaching law for the dynamic model are designed, and the control quantity is derived through differentiation, thereby realizing automatic control of indoor unmanned vehicle differential steering based on sliding mode variable structure. Experimental results demonstrate that the response position of the proposed method basically coincides with the given position, with an overshoot not exceeding 1% and a control time within 0.2 seconds, enabling precise and rapid control of the unmanned