The structural stability of the developer collaboration network is critical to the success of the OSS (Open Source Software) community. However, research on the structural stability of the evolving developer collaboration network in OSS communities is relatively insufficient. In this paper, according to the software version sequence, we construct the corresponding developer collaboration network of the Angular OSS community and then analyse this network's structural stability during network evolution. The results show that the network always presents an economical modular small-world structure during its evolution. The maintenance of the structure is related to a cohesive core, which is composed of two types of nodes (i.e., hubs and connectors). The hubs organize noncore nodes to form modules, while connectors facilitate the formation of inter-module connections. The overall results highlight the important role of core developers in the sustainable development of OSS communities and may provide a reference for community initiators to implement protection strategies for core developers.