The invention relates to a Cu-Ag alloy material for a motor communtator and a preparation method of the Cu-Ag alloy material, and belongs to the field of nonferrous metal processing. The material comprises components in percentage by mass as follows: 0.02%-0.035% of Ag, 0.002%-0.005% of Sn, 0.005%-0.01% of Zn, 0.005%-0.01% of Li, smaller than 5 ppm of O and the balance of Cu. The preparation and processing method of the alloy material comprises the steps as follows: a, burdening according to the mass percentage, charging, smelting and casting; b, hot rolling; c, milling; d, coarse intermediate rolling; e, intermediate annealing; f, acid pickling; g, finish rolling; h, stretch bending and straightening; and i, subpackaging and storing. The tensile strength sigma b of the Cu-Ag alloy is 380-450 MPa, the plasticity ductility delta is 6%-10%, the conductivity is larger than or equal to 96% IACS, the softening-resistant temperature is higher than or equal to 350 DEG C, and the use requirements of a current motor communtator material are totally met.