This study offers a quality-control supplychain model based on the "Internet Plus" paradigm. The model is based on principal-agent theory, which takes into account reputational damage from subpar products as well as external responsibility identification. The results of model analysis and simulation verification show that the optimal quality-control level and market price of agricultural products can be achieved in the agricultural supply chain based on "Internet +" if and only if the information platform's claim to the agricultural producer is less than the agricultural producer's claim to the delivery service provider (Wang M et al., 2019) . Furthermore, an increase in consumer claims or the agricultural producer's reputational damage as a result of inferior products will stimulate the quality control of an agricultural operation. Meanwhile, increased quality control will raise the market price of agricultural products