In this study, we consider a dual-channel supply chain with capital constraint consisting of one supplier and one capital-constrained manufacturer under the carbon tax policy. The capital-constrained manufacturer can make an order from the supplier based on trade credit financing, while is difficult to obtain loan to invest in carbon emission abatement. Three financing schemes are considered for the capital-constrained manufacturer in the dual-channel supply chain, including trade credit, supplier finance, and energy performance contracting. The results show that when the incompatible cost is lower than a threshold value, the manufacturer is more likely to choose energy performance contracting. However, with increasing of competition degree the manufacturer is easier to choose supplier finance. Furthermore, the supplier is willing to provide energy performance contracting when the incompatible cost is very low; otherwise is more willing to offer loan with obtaining interest from the manufacturer.