Construction industry has been included in pilot program since May 1, 2016 to pay value-added tax rather than business tax. Value-added tax is managed through invoices strictly and deductible withholdings on VAT has direct impacts on VAT bearing of enterprises. As a key part of construction cost, labor cost takes about 15%~25%, so large construction companies put great emphasis on whether they could get VAT special invoices. As management level and operation level separate from each other in construction companies, labor subcontracting has become the main form of construction in our country. By providing tax advices to several large construction companies on "business tax reform of VAT", the author investigated labor subcontracting in traffic construction projects, established cost-benefit model for establishing labor subcontracting enterprises by large construction companies in the article and conducted contrastive analysis on several labor employment ways, including internal establishment, external selection of labor subcontracting enterprises and labor dispatching.