Promoting land withdrawal of rural migrants is of great significance to both sustainable urbanization and rural revitalization in developing countries. Urban migration policies and rural land system arrangements are crucial influencing factors, but their interactive relationship and effects on rural land withdrawal have yet to be well understood. Focusing on China's hukou system reform aiming at reducing migration restrictions and homestead system reform aiming at granting farmers formal land property rights, we employ PSM-DID models on nationwide data from the rural household survey conducted in 2015, 2017, and 2019 to examine the causal effects of the joint reform on homestead withdrawal. The results show that the joint reform of these two systems can more effectively encourage rural migrants to withdraw from homesteads. Their complementary relationship arises because hukou system reform reduces migrants' access restrictions on urban welfare and equal employment rights, thereby weakening their reliance on the homestead security function and strengthening the income effect of homestead withdrawal. Interestingly, there is an inverted U-shaped relationship between hukou reform intensity and the change in this complementarity, indicating when homestead security is replaced by urban welfare, the higher expectations of future value and emotional attachment to homestead would reduce migrants' enthusiasm for homestead withdrawal. These findings highlight the necessity of simultaneously reducing migration restrictions and perfecting rural land property rights and propose specific implementation pathways for developing countries.