Inspired by the practice of platform retailers cooperates with blockchain technology service companies to improve the recycling rate of waste products and solve the three major pain points of recycling, this paper examines how the platform should optimize the combination of "permissioned blockchain technology (PBT) & sales format" to improve the economic, social and environmental (ESS) performance of the closed-loop supply chain (CLSC). The study first models and characterized the three major effects of PBT in the CLSC, namely trust effect, brand premium effect and recycling appeal effect. On this basis, the platform can choose to adopt a selling or agency selling format to help the upstream manufacturer sell products with or without PBT. Through analytic models, this paper investigates the impact of the implementation of PBT on product price, online service, brand goodwill, as well as demand and corporate profits. Through the comparative analysis of the platform's own profit, manufacturer' willingness to cooperate and the triple benefits of ESS in the CLSC, the optimal "PBT & sales format" combination strategy of the platform is obtained. The result indicates that when PBT effectively enhance consumer trust in the platform to recycle waste products and enhance brand favorability, the implementation of PBT has made a huge contribution to ESS. When the brand effect exceeds the reference price effect, the implementation of PBT will increase the retail price, exacerbating the double marginal effect, which is consistent with the conclusions of previous studies. When the reference price effect exceeds the brand effect, the introduction of PBT can alleviate the double marginal effect, which differs from previous studies. Another important finding is only when the commission rate is extremely low/relatively high, the manufacturer can reach a stable cooperation intention with the platform on selling/agency selling. And when the commission rate is in the medium and relatively low categories, the manufacturer's preferred sales model is different from the choice of the platform, the two can not achieve a permanent stable cooperation, and there is only a suboptimal equilibrium in the CLSC. Furthermore, combined with the platform sales cases of different categories of products, this paper derives the "PBT & sales format" combination strategy of platform enterprises for the universality of different attribute products
