Based on China's Land Economic Survey (CLES) data, empirical analysis was conducted on the impact of internet use on farmers' land transfer behaviors using models such as Eprobit, Eregress, and PSM-DID. The 4-way counterfactual total effect decomposition method was employed to verify the "synergistic" mechanism between the internet and social relationship networks. The research findings are as follows. Internet usage can further optimize land factor allocation and facilitate farmers' land transfer. Mechanism analysis indicates that strong social networks only have an intermediary effect, while weak social relationship networks have both intermediary and interactive effects, implying the transformation of the agricultural land transaction market. Further analysis reveals that the synergy between the internet and weak social relationship networks can effectively promote the transaction connection between small farm entities and new management entities. Internet usage leads to the long-term and contractualization of land market transactions. The results show that internet usage is of significant importance in weakening the constraints of social relationship networks and promoting the effective connection between small-scale agricultural economies and modern agriculture.