Cropland abandonment, a global economic and social trend spurred by rapid rural-urban transformation, has particularly affected China in recent years. Although it is widely believed that agricultural comparative returns primarily drive cropland abandonment, few scholars have explored the blocking effect of agricultural subsidies in this process. Based on CLDS large-scale farm-level panel data, this chapter employs a PSM-DID model to examine the overall effects, mechanisms and heterogeneity of agricultural subsidy reform on cropland abandonment. Results show that agricultural subsidy reform significantly reduced cropland abandonment, resulting in a 1.7% decrease in the proportion of cropland abandoned by farmers. The effect is mainly achieved by increasing the availability and income of agricultural subsidies. However, this effect is also moderated by agricultural comparative return and land titling, both of which weaken the impact of agricultural subsidy reform on cropland abandonment. Moreover, among farmers living in mountainous areas or lacking agricultural machinery, agricultural subsidy reform is negatively associated with cropland abandonment, while this relationship is not observed among other farmers. These insights into the role of agricultural subsidy reform in cropland abandonment can be leveraged to ensure food security in various countries.