Abstract: When two layers are produced together or separately, the output is very different. which is beyond the imagination of people. Study to the random percolation characteristics of stratified reservoirs may help to make reasonable analysis and Interpretation to some engineering problems, help to select the rational producing pressure differential. This paper presents the calculation equation and method of the sidewall pressure and the plane flow of every layer, assuming that cross flow does not exist among the homogeneous reservoir with n-layer infinite extension planes, and the initial pressure of each layer is or is not the same. Taking a two-layer reservoir as an example, this paper uses the Stehfest Numerical Inversion Method to have calculated the plane flow under constant output and pressure respectively, presents the "backflow" variation curve when the initial pressure at each layer is different.