Farmers' off-farm working choices have a profound impact on family land use behavior under the rapid urbanization in China. This paper studies the mechanism of off-farm employment affecting farmland allocation behavior and focuses on the role of risk. Based on the Chinese Family Panel Studies (CFPS) data, Probit and Tobit models were used to empirically test the impacts of off-farm employment on farmers' land renting behavior, and instrumental variables were applied to test the stability of the models. The results show that households who join off-farm employment are more likely to rent land out, and they are more willing to rent out land to relatives or neighbors in the oral, informal, rent-free or low-rent contracts. But the incentive to rent out land won't increase with households’ off-farm level enhancing. The existence of unemployment risk will prevent farmers from land renting out, especially for farmers who mainly work in off-farm sectors. Besides, with the development of agricultural productive services, the workplace no longer has an impact on land rental behavior. In general, addressing the risk of loss of land rights and unemployment faced by farmers will effectively promote the development of rural land leasing market.