The invention adopts the technical scheme that a production method for high-strength alloy R320Cr steel rails comprises the steps of molten iron desulphurization, converter smelting, LF refining, RH refining, continuous casting and rolling. The production method is characterized in that in the converter smelting step, the content of C in tapped steel is controlled to be 0.01-0.02%, and the tapping temperature is controlled to be 1640-1670 DEG C; in the continuous casting step, constant pulling rate operation is adopted, and the pulling rate is controlled to be 0.6-0.7 m/s; meanwhile, super-weak cooling preparation water is adopted in a secondary cooling section, and the specific water flow is controlled to be 0.15-0.25 L/kg. By adopting the production method disclosed by the invention, the holo-aluminium content in R320cr steel is controlled to be 0.0025%-0.0035%, so that the anti-fatigue ability of the steel rails is improved; the yield of Cr alloy is more than 90%, so that cost is reduced; the heating time of LF refining is 40-50 minutes, and the LF refining can be matched with the continuous casting, so that the production tempo is totally met, and the qualification rate of occluded foreign substance reaches 100%. The extension strength Rm of the obtained R320Cr steel is 1130-1190 MPa; the percentage elongation A after fracture is 9%-12%; and the surface hardness is 325-355 HB, so that a high-quality high-strength alloy R320Cr steel casting blank which can meet product requirements is obtained with low cost.