Abstract: Agricultural production service outsourcing is an important embodiment of division evolution and an important guarantee for promoting large-scale operation of agricultural land and realizing agricultural and rural modernization．Based on 623 survey data of rice farmers in Northeastern Area, influencing factors and mechanisms of social trust on decision-making degree of rice farmers for production service outsourcing were empirically tested．Results showed that social trust had a significant impact on production service outsourcing behavior and decision-making degree of rice farmers, and both non-agricultural employment and marketization levels positively regulated promotion effect of social trust on production service outsourcing decision-making degree of rice farmers．Heterogeneity analysis showed that social trust of rice farmers with low planting scale had a stronger influence on a deepening of production service outsourcing decisions．In view of this, suggestions were proposed for countermeasures: improving village and township organization platforms construction to enhance social trust level of rice farmers, building a production service outsourcing system to promote specialized division of labor in agriculture, providing more non-agricultural employment opportunities to broaden information-access channels for rice farmers, and opening up marketing competition to raise marketization level．