In Wireless Mesh Network (WMN), load balancing is an important factor to build a multicast routing protocol. In this paper, the authors propose a new Multi-Objective model for multicast load balancing optimization in wireless mesh network. This model called Path-MeshRouter-Gateway Load Balancing (PMRGLB), which aims to achieve four objectives, i.e. minimizing the total cost of the network, minimizing path length, minimizing gateway load balancing, and minimizing path interference. This optimization problem is solved simultaneously by using a meta-heuristic method. Simulation result shows the effective of this model compare with others.