Subcontracting won the bid. The tender documents will clearly stipulate that the project contractor can participate in the bidding in the form of consortium or subcontract. In the process of bid evaluation, the tenderer will score according to the comprehensive factors such as the technology, experience and reputation of each bidder, and make a comprehensive evaluation based on the tender offer, and finally determine the winning bidder. Subcontractors have outstanding professional skills and engineering construction experience, or they can provide more favorable quotations, making it easier to win the bid.