Cap-and-trade has become one of the most widely used carbon emission limitation methods in the world. Its constraints have a great impact on the carbon emission reduction decisions and production operations of supply chain enterprises, as well as profit distribution. In the construction supply chain, there are few studies on the profit distribution and emission reduction decisions considering cap-and-trade policy. This paper investigates the profit distribution model of a two-echelon construction supply chain consisting of a general contractor and a subcontractor with cap-and-trade policy. Using game theory and Shapley value method, the optimal emission reduction decisions and profit distribution under three cooperation modes of pure competition, co-opetition, and pure cooperation are obtained, respectively. The research shows that the profits of the construction supply chain are increasing in pure competition, co-opetition, and pure cooperation scenarios, and the emission reduction amount of the construction supply chain in the case of pure cooperation is greater than that of pure competition and co-opetition. The carbon emission reduction amount under the co-opetition scenario is not always greater than that under the pure competition scenario, which depends on the emission reduction cost coefficient relationship of general contractor and subcontractor. When the cost coefficient of emission reduction of the general contractor is less than that of the subcontractor, the emission reduction amount under pure competition is larger than that under co-opetition. A numerical study is carried out to verify the conclusions and illustrated the profits of the supply chain decreased with the increase of carbon emission reduction cost coefficient, and had nothing to do with the emission reduction efficiency of enterprises.