This article is established in the Max-profit for both tender and bidder,to their "Win-Win".The most concerned factors-cost,time,quality are taken as the incentive factors at the same time,and are combined in a mathematics model.By using the CPIF contract,the authors establish Stackelberg decision to incentive the both,and then optimize their both profits.Then,they introduce how to use genetic algorithms to compute the model.Finally,the model is illustrated coith an example.