For the inter-cell wireless resource management in macro-micro co-networking, proposed is a joint transmission and dynamic spectrum allocation strategy based on micro cell clustering in massive MIMO system. The strategy is implemented in two steps to optimize the network weighted sum rate. First, the proposed algorithm performs micro-cell clustering according to the current channel state information (CSI) of users, so as to reduce the inter-cell interference as much as possible and improve the system capacity. Then, the macro base station (MBS) and each micro-cell cluster dynamically allocate sub-carriers to its service users according to the current traffic request information to maximize the network weighted sum rate and improve the resource utilization. The simulation results show that the proposed micro-cell clustering and dynamic spectrum allocation strategy can not only effectively improve the system throughput but also reduce the interference among users in macro-micro collaborative networking.