Microgrids are increasingly participating directly in the electricity market as sellers in order to fulfill the power demand in specific regions. In this study, we consider a demand response management model for multi-microgrids and multi-users, with overlapping sales areas. We construct a Stackelberg game model of microgrids and users, and then analyze the equilibrium strategies systematically. As such, we prove that there is a unique Stackelberg equilibrium solution for the game. In equilibrium, the electricity price strategies of the microgrids and the demand strategies of the users achieve a balance. Furthermore, we propose a numerical algorithm, supported by a simulation, to compute the equilibrium solution and give the proof of convergence.