Flow control is an important means of avoiding congestion and providing QoS guarantee in networks. In this paper, a differentiated pricing scheme for flow control in General Multiuser Access Networks (GMAN) is proposed. Under this scheme, the problem of optimizing the network performance is formulated as a two-level hierarchical network game. By employing the Gerolamo Cardano Formula, we obtain the Complete Solution (CS) of the optimal prices and users’ flow. Simulation results show that the proposed solution can enhance the revenue of Network Service Provider (NSP) and the network performance without significantly affecting user satisfaction, in comparison with the Asymptotical Solutions of Tamer Basar (AS-TB) in linear network systems. Moreover, analytical solution can also be obtained by CS, even with fixed NSP capacity. This feature makes our CS applicable to practical communication networks.