In the control architecture of the platoon system, the interaction of the information between the vehicles is determined by the information flow topology. However, the current studies on platoon control are often restricted to a specific information flow topology. This paper proposes a distributed sliding mode control (DSMC) strategy for a platoon under bidirectional multi-vehicle information flow topology. Firstly, the platoon control is decomposed into upper level and lower level controllers by hierarchical strategy. In contrast to the lower controller, which uses an inverse dynamics model to achieve the consistency of the actual acceleration and the expected acceleration, the upper DSMC strategy optimizes expected acceleration. Topological sliding surface design and topological reaching law design constitute two components of the upper DSMC strategy. The topological sliding surface is defined by weighted summation of errors, and the topological reaching law is defined based on the information flow topology. In addition, the stability of the platoon is proved by Lyapunov function. On this basis, the effectiveness of the proposed DSMC strategy is verified on the Carsim/Simulink platform under the typical bidirectional multi-vehicle information flow topology.