In the evolving economy, the concept of sustainable development gaining popularity, consumers increasingly favor quality agricultural products that are flavorful, nutritious, and sustainably produced. At the same time, the rise of online channels, fueled by internet and mobile payment technologies, offers diverse shopping experiences but also amplifies trust issues. Due to the experiential and trust characteristics of some quality information of agricultural products, it’s difficult for consumers to make comprehensive and accurate judgments on the quality of agricultural products. As a result, some unscrupulous operators intentionally using deceptive means to pass off low-quality agricultural products as quality ones for profit. The prevalence of unscrupulous operators driven by profit motives has exacerbated the counterfeiting of quality agricultural products. However, blockchain-based traceability systems offer a dependable method for consumers to authenticate product quality, presenting a robust solution to address trust concerns.Focusing on the problem of counterfeiting in the market of quality agricultural products in a dual-channel sales context, a Stackelberg-Nash game model was hereby constructed to investigate the sales behavior of different distribution channels in the quality agricultural product market, and the underlying reasons for the counterfeiting were further analyzed. Subsequently, differences in counterfeiting behavior among different channels and their underlying causes by comparing, as well as the adoption strategies of blockchain technology were analyzed, and the findings were verified by combining with numerical simulation.The analysis reveals that: 1) The online counterfeiting rate for quality agricultural products tends to be higher than offline. However, in situations where agricultural products with lower perishability and online returns are more convenient, the online counterfeiting rate may actually be lower than offline. 2) The harder the quality agricultural products can be distinguished, the less the offline and online retailers ordering, and the higher the counterfeiting rate. As a result, quality farmers, offline retailers, and online retailers have a stronger willingness to adopt blockchain technology. Information asymmetry, preventing consumers from making comprehensive and accurate judgments on agricultural product quality, serves as the root cause of serious counterfeiting and resulting loss of benefits for quality agricultural product operators. 3) The higher the yield uncertainty of quality agricultural products, the less the offline and online retailers ordering, and the higher the counterfeiting rate. As a result, quality farmers, offline retailers, and online retailers have a stronger willingness to adopt blockchain technology. The uncertainty surrounding the yield of quality agricultural products impacts both production and marketing incentives for operators, thereby exacerbating counterfeiting within the agricultural market. This ultimately undermines the adequate supply of quality agricultural products. 4) The higher the online distribution loss rate, the more the offline retailer ordering, and the lower the counterfeiting rate, while the offline retailer′s willingness to adopt blockchain is weaker. Conversely, when online distribution loss decreases and offline retailer ordering decreases as a result, the counterfeiting rate tends to increase. In this scenario, the online retailer′s willingness to adopt blockchain technology is stronger. The willingness of operators to adopt blockchain technology is not always directly proportional to the counterfeiting rate. The online distribution loss of agricultural products not only exacerbates counterfeiting in online channels but also suppresses the enthusiasm of online operators to use blockchain technology to combat counterfeiting. 5) There exists an equilibrium region, in which the adoption of blockchain technology can achieve a Pareto improvement in the supply chain. When the online distribution loss rate is low, implementing blockchain technology can lead to a Pareto improvement. Otherwise, only when the quality of quality agricultural products is high, can the adoption of blockchain technology facilitate a Pareto improvement in the supply chain. 6) From a long-term perspective, the equilibrium region for the adoption of blockchain technology is expanded, and its adoption yields even more significant gains to the supply chain.