Abstract: The security of cultivated land resources is important for maintaining social stability and national food security. Cultivated land protection policies are programs of action maintaining value until they are implemented. As such, their effectiveness can only be realized through an actual implementation. We analyzed and quantified the effects of cultivated land protection policy (CLPP) implementation, provide data and decision support to improve the evaluation of CLPP implementation, and expand the improvement and innovation of the evaluation method for land policy implementation. We constructed an evaluation index system for the implementation effect of CLPPs and used the accelerating genetic algorithm projection pursuit model to reveal the level of CLPP implementation in Chinese 30 provinces (autonomous regions and municipalities), excluding Hong Kong, Macao, Taiwan, and Xizang. The spatiotemporal variation law of CLPP implementation was explored using an exploratory spatial data analysis model, trend surface analysis, and spatiotemporal transition technology. The results showed the following: 1) The level of CLPP implementation in various provinces (autonomous regions and municipalities) demonstrated a trend of decreasing first, then increasing and then decreasing. 2) Regarding the spatial pattern, the CLPP implementation effect exhibited spatial structure of being “high in the eastern region but low in the western region” and being “high in the southern region but low in the northern region” in the east-west direction and the north-south direction. 3) Regarding spatial correlation, the CLPP implementation effect had spatial agglomeration and heterogeneity across countries. Furthermore, the effect transition of the CLPP exhibited path dependence and spatial lock-in characteristics. 4) Regarding the decomposition components, the constraints were the cultivated land production function, social security function, and supervision level. Given these conditions, the implementation of CLPP must be improved. Furthermore, it is restricted by background conditions and the environment of the cultivated land in each region. Therefore, governance strategies must be formulated based on the local conditions.