Taking into consideration the cooperative problem in complex project teams，this paper establishes an indirect evolutionary game model incorporating with altruism preferences and finite groups，and studies the interaction and evolution of selfishness and altruism preferences in a complex project team． The results show that: for projects with higher unit effort costs，agents can be efficiently motivated towards altruism by smaller teams，higher profits shares，and other spiritual benefits from altruism; in contrast，for projects with lower unit effort costs，higher profit share and spiritual benefits from altruism will not lead agents to be altruism or even potential altruism． Finally，the theoretical results are verified by a simulation and policy suggestions are made for managers aiming at promoting altruism in a complex project team．