The digital low-carbon transformation and high-quality development of the construction industry are regarded as inevitable. The industrial application of the closed-loop supply chain of construction machinery was considered under the carbon trading policy and the industrial Internet platform. Decentralized and centralized decision-making models of the closed-loop supply chain of construction machinery leasing were constructed, and a leasing compensation-joint emission reduction contract was designed to coordinate the supply chain. Combined with numerical example analysis, more intuitive management enlightenment was provided for the optimal strategy of the supply chain. The results indicate that the rent compensation-joint emission reduction contract can be used to reduce the gap between the supply chain profit under decentralized decision-making and centralized decision-making. When the emission reduction ratio and compensation are within a specified range, the joint contract is shown to achieve Pareto improvement in the profit of supply chain members. It is also demonstrated that when the preference coefficient of remanufactured products, the sensitivity coefficient of product maintenance, and the price of carbon trading are increased, the demand for remanufactured products is enhanced, and the carbon emissions of the supply chain are reduced.