In this work, we presented numerical modeling for the bulk heterojunction polymer solar cells (BHJ) based on the finite difference method to obtaining the BHJ characteristics. Our model for the BHJ, where the electron donor and acceptor materials are mixed in a solution, is two separate domains with gaussian shape interface. In this model we consider a two-dimensional geometry of thickness L on y-axis and periodic along x-axis. We assume that the rate of exciton generation to be homogenous throughout device. Some of obtained characteristics are the density of electrons and the density of the holes, current density, open circuit voltage and short circuit current density.