In this paper, a more accurate model of porous regenerator based on Brinkman-Forchheimer-extend Darcy momentum equation is built. The dissipative term caused by permeable resistance is kept in the energy equation. The introduced parameter K, the permeability of the porous medium, with the porosity, can describe the essential geometry property of tortuous porous medium completely. With the boundary conditions, the expressions of oscillating velocity and temperature are obtained after linearizing and solving the governing equations with the small oscillating amplitude approximation. Based on these expressions, the total energy flow is derived. The temperature gradient of the regenerator is solved by using the total energy flow expression. Moreover, the temperature difference between the ends of porous regenerator is calculated in a standing-wave thermoacoustic heat pump. The simulated results are compared with ones based on Swift’s linear theory and experiments conducted by S. Mahmud et al. It can be inferred that the simulated results are more accurate than ones of Swift’s linear theory and agree with the experiments very well. Therefore, the model developed in this paper is helpful for the computation of other thermoacoustic systems using tortuous porous media as regenerator.