Blockchain technology (BCT) can alleviate information asymmetry between banks and enterprises while enhancing product traceability in dual-channel supply chains. Considering the effects of information asymmetry mitigation and market potential incentives offered by BCT, we construct a game model of the capital-constrained dual-channel supply chain consisting of a manufacturer, a retailer, and a bank. The equilibrium decisions and profits of each participant in the two scenarios, no BCT adoption (Scenario N) and with BCT adoption (Scenario T), are derived. Further, the impact of BCT adoption on retailers' financing environment and the equilibrium results are obtained through comparative analysis. Several findings are obtained: First, BCT can improve the financing environment for the retailer by reducing financing gaps and costs. Second, the market potential incentive effect of BCT positively affects all participants, as it allows for increased market potential in both channels. Third, the information asymmetry mitigation effect does not positively affect all participants: it is always favorable to the high-quality retailer and bank, while it is always unfavorable to the low-quality retailer. It is only favorable to the manufacturer when the retailer's own capital is relatively large. Finally, smart contracts can help the bank avoid moral hazard, further boost the positive effects of information asymmetry mitigation effects on the high-quality retailer and the bank. The findings may have implications for BCT adoption decisions to facilitate inclusive finance and supply chain traceability.