Abstract: Due to the problem of cross-tier interference affects Macrocell users in heterogeneous network, We propose a method that relying on cooperative communication technology to weaken the influence, it is to improve the downlink performance of Macrocell users through MBS and Femtocell users' cooperative diversity, but also a relay selection strategy based on the principle of soft switching is proposed. Theoretical analysis and simulation results show that the cooperative communication technology based on Femtocell users is significantly superior to the direct transmission in terms of the performance of Macrocell users.