One of the objectives of agricultural production trusteeship subsidy is to make up for the limitation in agricultural production trust by subsidizing small farmers to purchase trust services for key and weak links in crop production and guide farmers to change their production mode from single-link trusteeship and multi-link trusteeship to whole process trusteeship. Based on the field survey data of the pilot areas of agricultural pest control subsidy in Jiaxing city of Zhejiang province,Changde city of Hunan province and Suzhou city of Anhui province,the article analyzes the impact of subsidies for weak links of agricultural production trusteeship on farmers’ willingness of whole process trusteeship and also screens the differences in the impact of subsidies on farmers with different degrees of household land size and old age. The results show that the weak link of agricultural production trusteeship subsidy has a positive effect on farmers’ willingness of whole process trusteeship against the background of a high proportion of trusteeship in labor intensive production links such as cultivation and harvesting. The higher level of cognition toward benefit of weak link trusteeship and farmers’ education,the higher level of farmers’ willingness of whole process trusteeship. The part-time farmers have higher willingness of whole process trusteeship than pure farmers. With the moderating effect of farmers owning agricultural machinery,the positive effect of large-scale of agricultural land on farmers’ willingness of whole process trusteeship is gradually weakened. The subsidy has significant impact on farmers’ whole process trusteeship,which is mainly reflected in the high-scale group of agricultural land and high-age group. Therefore,the government should expand the coverage of subsidies for the weak link of agricultural production trusteeship and especially focus on the farmers’ families which have higher land scale and higher degree of aging. The government should standardize services and lower the service price,in order to shift farmers’ agricultural operation from labor intensive trusteeship and technology intensive trusteeship to whole process trusteeship.