In this paper, a distributed game-based formation control method for a set of assembly modules is proposed to form a desired configuration during on-orbit assembly. Considering different interests of individual assembly modules, formation control is modeled as a noncooperative game with control constraints and collision avoidance, where each module establishes its strategy to interact with other modules during the process of formation control. In order to get Nash equilibrium, the game problem is reformulated into a game problem in receding predictive horizon and simplified into Quadratic Programming (QP) formulation. An illustrative example is given to validate the effectiveness of the distributed game-based formation control method in tackling with the assembly of modules.