AI technology has become a key means to improve product quality information disclosure, alleviating information asymmetry in supply chains. This study investigates a two-echelon supply chain in which a single supplier interacts with two competing retailers that are differentiated in terms of product quality. Four AI adoption strategies are considered, including non-adoption of AI by both retailers (NN), AI adoption only by the high-quality retailer (AN), AI adoption only by the low-quality retailer (NA), and AI adoption by both retailers (AA). We further analyze how key factors, such as quality competition intensity, AI efficiency coefficient, AI investment level and information asymmetry degree, affect supply chain decisions and optimal AI adoption strategies of all supply chain members. The results reveal that the high-quality retailer always benefits from AI adoption and gains the highest price premium under the AA strategy. In contrast, the low-quality retailer can achieve positive profits only when the fixed cost of AI platforms is below a critical threshold. The supplier achieves optimal profits under the AA strategy with moderate competition and under the NA strategy with intense competition. Core parameters such as the AI efficiency coefficient and information asymmetry jointly influence corporate AI adoption decisions, and the NN strategy is preferred amid severe information asymmetry.

This paper constructs a dual-channel Stackelberg game model including the benchmark wholesale model B, the manufacturer encroachment model E, and the front-end and back-end AI-enabled model A. Through comparative static analysis, it is found that the manufacturer's encroachment profit increases with the increase of consumers' green preferences and channel substitutability. When the effective market capacity is positive, the manufacturer's profit under the encroachment strategy is better than that of the benchmark model, and the retailer's profit under the encroachment model is not lower than that under the benchmark model. Additionally, the optimal AI investment increases monotonically with the effective market capacity and efficiency parameters and decreases monotonically with the cost coefficient. When reaching a certain threshold, it shows a significant upward trend. Moreover, the stronger the channel substitutability, the lower the threshold. Under given constraints, the profits of both the manufacturer and the retailer in model A are significantly higher than those in other models. Therefore, moderate front-end and back-end AI collaboration is the key to achieving the triple goals of "encroachment + green + digitalization" and achieving a win-win profit situation between the manufacturer and the retailer. This provides a theoretical basis for enterprises to design direct sales strategies, AI investment intensity, and for governments and platforms to formulate subsidy and cost-sharing policies.