The invention discloses a modulation mode collaboration method for a large-scale antenna system. The method comprises the following steps of step 1.setting the total number of cells as L, arranging abase station to each cell and M antennas to each base station, making a user of each cell send an uplink pilot sequence for the base station to complete channel estimation, and then carrying out QAM modulation on a transmitted signal by the kth user of the lth cell; step 2.computing a relation gammaki of kth users of all cells; and step 3.selecting optimal modulation modes Nk1, Nk2 to NkL capableof maximizing (formula) from an available modulation modes obtained in the step 2. According to the method, the restrictive relation between the modulation mode of the user and path fading is calculated, so that the available maximum modulation order of each user is obtained, and thus the system capacity can be effectively improved, the interference between the users of the large-scale antenna system is reduced, and an error rate of demodulation of the signal at a receiving end by a transmitting end is reduced.