The invention belongs to the field of low-smoke halogen-free flame retardant materials, and particularly relates to an irradiation crosslinking halogen-free flame retardant polyolefin material for locomotive wires and a preparation method of the irradiation crosslinking halogen-free flame retardant polyolefin material. The polyolefin material comprises the following components in parts by mass: 20-30 parts of ethylene-vinyl acetate copolymer, 10-20 parts of polyolefin elastomer, 5-10 parts of a macromolecular compatilizer, 45-65 parts of an inorganic flame retardant subjected to surface modification treatment, 5-10 parts of a flame retardant synergist, 0.8-1.5 parts of an antioxidant, 1.5-2.5 parts of silicone masterbatches, 0.3-0.6 part of a crosslinking sensitizer, 1.5-2 parts of carbon black and 1-2 parts of a processing aid. The preparation method comprises the technological steps of surface treatment of the inorganic flame retardant, proportioning, mixing, melting, extrusion for pelletization, and the like. Compared with the prior art, the polyolefin material has the characteristics of excellent flame retardation (capable of passing the D type group burning test), oil resistance (mineral oil and fuel oil resistant), high temperature resistance (the grade is 150 DEG C), ultraviolet resistance, scratch resistance, low corrosion, low toxicity, environment friendliness, excellent processing performance, extrusion speed capable of reaching 100-150 m/min, and bright surface.