Ecological networks play a crucial role in shaping regional ecological security patterns and restoring territorial ecological spaces. Exploring and revealing the spatiotemporal evolution of the ecological network in the Guangdong - Hong Kong - Macao Greater Bay Area (GBA) and simulating and predicting its future development trends are of great significance for optimizing the spatial layout structure of the GBA and coordinating the relationship between socio - economic development and ecological environment protection. This study integrated the Patch-generating Land Use Simulation (PLUS) model, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Model, and the Minimum Cumulative Resistance (MCR) Model to investigate the spatial-temporal evolution characteristics of the ecological networks in the GBA from 1985 to 2020. Additionally, it predicted the trends in ecological network changes for 2035 and 2050 under inertial development, urban expansion, cultivated land protection, and ecological conservation scenarios. The results indicated that: (1) The ecological sources in the GBA exhibited a spatial pattern of "sparsity in the center and density around the perimeter." Between 1985 and 2020, both the ecological source areas and the ecological network connectivity showed an "M"-shaped fluctuating downward trend. This decline was primarily driven by the continuous expansion of urban construction land and infrastructure. Ecological sources followed a complex sequence of "contraction-disappearance-restoration-expansion." (2) The construction of transportation infrastructure, such as highways, in urban inter-junction areas was the primary cause of significant changes in ecological corridors. The development of these facilities increased the connectivity resistance within the regional ecological network and altered the continuity and alignment of ecological corridors. Consequently, this raised the costs associated with material circulation, energy flow, and information transfer between ecological source areas, leading to a decline in the overall connectivity of ecological networks in the GBA. (3) Under the scenarios of inertial development, urban expansion, and cultivated land protection, the ecological source areas and the ecological network connectivity in the GBA both showed a declining trend by 2035 and 2050. The ecological network was further damaged, and its structure became more fragile. Among these scenarios, the cultivated land protection scenario showed the largest decline, with the indicators for the ecological source areas and the ecological network connectivity being significantly lower than those in other scenarios. In contrast, under the ecological protection scenario, the ecological source areas and the ecological network connectivity recovered, and the integrity and stability of the ecological network were significantly improved and enhanced. Therefore, in future land use policies and planning for the GBA, it is essential to strike a balance between the development of construction land, the protection of cultivated land, and the restoration of ecological land. These findings provide a scientific basis for optimizing the territorial spatial structure and ecological network patterns in the GBA and for formulating land development policies that align socio-economic development with ecological protection.