Guangxi is a typical ecological resource-rich and economically underdeveloped region in China, facing the issues of uncoordinated ecological and economic development. In order to achieve a synergistic enhancement of ecological background protection and ecological value transformation, as well as to promote sustainable economic and social development, it is particularly important to clarify the spatiotemporal evolution and intrinsic influencing mechanisms of the forest ecological product value (FEPV) in Guangxi, as well as to understand their characteristics and developmental advantages. For this study, the FEPV in Guangxi was calculated based on multi-source data, its spatiotemporal evolution characteristics were analyzed, the main influencing factors of FEPV were identified using geographic detectors, and the spatial heterogeneity of the influencing factors was explored using the Geographically and Temporally Weighted Regression (GTWR) model. The results showed the following: (1) From 2010 to 2020, the total amount of FEPV in Guangxi exhibited an upward trend, with an average annual growth rate of 9.45%. Regarding the composition of the total FEPV, regulating service value contributed the most, while the supply and cultural service value had great growth potential. The spatial pattern of FEPV was “high in the north and low in the south”, with Guilin being the extreme area and Hechi and Baise being high-value areas. (2) From the single-factor detection results, the dominant factors affecting the spatial evolution of FEPV were the elevation, forestry primary output value, and annual average temperature, while the explanatory power of social factors was relatively weak. From the bivariate factor interaction detection results, the dominant combination factors were annual precipitation ∩ forest coverage, annual precipitation ∩ forestry primary output value, elevation ∩ forestry primary output value, and annual precipitation ∩ forestry primary output value, with explanatory degrees (qs) of 0.89, 0.90, 0.87, and 0.89, respectively. (3) Annual precipitation and forest coverage were positively correlated with FEPV, and the influence intensity generally increased from south to north. Population density was negatively correlated with FEPV in general, and the influence intensity showed a negative trend from the periphery to the center. The research results provide a reference for the realization of ecological product value and the green and low-carbon transformation of related industries in similar regions.