Proposed in this paper is a multiple access technology based on bivariate Chirp modulation,which makes use of both the Chirp rate and the initial Chirp phase to furtherest suppress the multiple access interference with small system gain. When the Chirp rate differences are small,this method can ensure the orthogonality of multiple access signals by distinguishing different initial phases. Moreover,the effect of the mutual correlation of multiple access users' Chirp signals on the bit error rate ( BER) is discussed,and the superiority of the initial phase factor in constructing the multiple access signal basis is analyzed, Simulated results show that,as compared with the existing multiple access technologies based on Chirp spread spectrum,the proposed one is more effective because it suppresses the multiple access interference and permits more multiple access users to simultaneously access the system without obviously degrading the BER performance.