A cold-rolling technology for manufacturing an admiralty brass C44300 oil-well pump cylinder blank pipe comprises the following steps that (1), an admiralty brass raw material pipe is put into a polishing machine, the outer surface of the pipe is polished and pretreated, and defects are removed; (2), the pretreated admiralty brass pipe is rolled through a two-roller cold rolling pipe machine, pass deformation is controlled to range from 37 percent to 43 percent, the rolling speed is 80 times/min, the feeding speed ranges from 0.25 m/min to 0.32 m/min, the temperature of rollers ranges from 60 DEG C to 80 DEG C, and the inside dimension tolerance is controlled to +/-0.05 mm; and (3), a mechanical performance test is carried out on a rolled finished product, the standard-required tensile strength larger than or equal to 310 MPa, and the standard-required yield strength larger than or equal to 105 MPa are achieved, and then, the finished product is put into a warehouse. By means of the method, acid pickling is not needed, the two-roller rolling machine is adopted to carry out large-deformation rolling, and forming can be achieved through one-pas rolling. Due to the fact that technologies of multi-time annealing, acid pickling and the like are avoided, energy consumption cost caused by acid liquor and annealing is greatly reduced; the yield of the admiralty brass C44300 pipe is improved; the inner and outer surface roughness is high, and the inside dimension tolerance is controlled to +/-0.05 mm; and abrasion of various kinds of devices is reduced, and the service life of the pipe is prolonged.