As a novel developing vacuum electronic device, sheet beam traveling wave tube has a wide range of application prospects in the field of radar and communications. Compared to cylindrical beam devices, there are still fewer beam-wave interaction models for sheet beam traveling wave tubes. Based on the electric circuit principles, a hybrid circuit model consisting of distributed transmission line components and lumped elements for a commonly used sheet beam slow wave structure(SWS)—staggered double vane is developed, and the feasibility of applying the model to high frequency SWS is validated. The problem of mapping from the geometrical parameters of SWS to the physical parameters of hybrid circuit is focused on. The hybrid circuit model of staggered double-vane is developed, and its dispersion relation is analyzed. Besides, a model-based Simulated Annealing(SA) algorithm procedure, capable of achieving high precision parameter fitting is coded. The results show that the proposed hybrid circuit model can accurately reproduce the dispersion characteristics of the staggered double-vane. It is significant for the subsequent development of a large signal sheet beam-wave interaction procedure based on the hybrid circuit model.