The invention belongs to the technical field of polypropylene fiber production. Aiming at the problem that the existing red pigment is not easily dispersed in the polypropylene raw material mixture, which causes the color difference of the polypropylene fiber, the invention provides a polypropylene raw material mixture in which the red pigment is fully dispersed and a preparation method, which consists of the following The composition of each component in mass percentage: polypropylene powder ≥ 48%, red pigment 27-30%, polyethylene wax ≥ 17%, electrostatic agent 0.95-1%, silicone powder 0.05-0.1% and zinc stearate 2.5% ~3%, the sum of the mass percentages of the above-mentioned components is 100%, the softening point of polyethylene wax is ≥120°C, first rotate and mix at low speed during preparation, and then fully rotate and mix at high speed. The permanent brilliant red in the polypropylene raw material is fully dispersed, no raw powder is produced, the aging time is prolonged, and the service life of the spinning assembly is improved. The color of the obtained polypropylene fiber is good, there is basically no color difference, and the amount of waste yarn is also greatly reduced.