Abstract: Considering the variations of porosity and permeability of rapeseed cake and rapeseed dehulled cake in pressing, one-dimensional partial differential equation for fluids in porous media of rapeseed cake and rapeseed dehulled cake was developed on the basis of theory of fluid-solid interaction, in which the cake is deformable and the permeability is variable. An analytic solution for problem of fluid-solid interaction of one-dimensional steady flow in porous media was proposed. The parameter inversion problems of permeability model of rapeseed cake and rapeseed dehulled cake, by using improved simulated annealing, were researched. The results demonstrate that the distributions of pore pressure and permeability in the cake are nonlinear, exponential function can be used to simulate the relationship between permeability and effective stress well, and the permeability of rapeseed cake is greater than that of rapeseed dehulled cake.