Abstract: A thorough understanding of the spatial differentiation and evolutionary characteristics of rural territorial multifunctionality provides an important scientific basis for advancing comprehensive rural revitalization according to local conditions. Taking 42 county-level units in the Songnen Plain as the research area, this study constructed an evaluation index system for rural territorial multifunctionality and comprehensively employed spatial autocorrelation analysis, kernel density estimation, and geographical detector to examine the spatio-temporal evolution and influencing factors of rural territorial multifunctionality from 2008 to 2023. The results show that: 1) The overall level of rural territorial multifunctionality in the Songnen Plain showed a steady upward trend, with the mean value increasing from 0.231 in 2008 to 0.386 in 2023, representing an increase of 67.09%. Significant spatial agglomeration was observed, but its intensity showed a dynamic pattern of initial strengthening followed by weakening, gradually forming a spatial differentiation pattern with relatively high levels in the south and relatively low levels in the northeast. 2) The four rural territorial functions exhibited distinct evolutionary characteristics. The agricultural production function increased overall but showed greater regional differentiation, the economic development function underwent a phased shift from southern agglomeration to northern expansion and then southern contraction, the social security function experienced the most substantial improvement, and the ecological conservation function declined slightly overall. 3) Per capita GDP, secondary industry added value, industrial structure, and mean annual temperature were the major factors influencing the spatial differentiation of rural territorial multifunctionality. The interactions among all factors exhibited enhancement effects, characterized by bivariate enhancement or nonlinear enhancement, indicating that the evolution of rural territorial multifunctionality resulted from the combined effects of multiple factors, including the natural environment and socioeconomic conditions. The findings provide empirical evidence for the coordinated enhancement of rural territorial functions, differentiated county-level development, and the targeted advancement of comprehensive rural revitalization in the Songnen Plain.