Abstract: In order to provide physical parameters of the corn straw for the simulation of flow field inside the device, the corn straw was pretreated by the device of screw extrusion and continuous steam explosion. The rheological properties of acquisitions were tested by using a capillary rheometer. The rheological curves of two types of pretreated corn straw and their influence of temperature were investigated. Three rheological models including Bingham model, Casson model and Power law model were used to simulate the rheological parameters of the acquisitions. The results showed that both of the acquisitions had obvious phenomenon of shear thining, they were a kind of pseudoplastic fluid. When the shear rate was low, the effect of temperature on the rheological curves was inapparent. When the shear rate was high, the effect of temperature on the rheology curves was apparent. The results of linear fitting showed that the fitting effect of the acquisitions conducted by the power law model was the best and Bingham model was the worst. The power law model equation of the acquisitions can be used for flow field simulation with higher accuracy. The result can provide a reference for the research of flow state of acquisitions in single-screw extrusion and enzymolysis device.