The invention discloses a flux-cored wire steel strip and a production method thereof and belongs to the technical field of metallurgy. The flux-cored wire steel strip comprises, by mass, smaller than or equal to 0.04% of C, 0.15%-0.35% of Mn, smaller than or equal to 0.040% of Si, smaller than or equal to 0.008% of S, smaller than or equal to 0.012% of P, 0.020%-0.035% of Al, smaller than or equal to 0.0030% of N, smaller than or equal to 0.0050% of O, and the balance Fe and inevitable impurities. The production method comprises the specific steps of molten iron desulphurization, converter smelting, secondary refining, continuous casting, continuous cast billet heating, hot rolling and curling working procedures. The method is characterized in that in the secondary refining working procedure, the mass fraction of O is controlled to be smaller than or equal to 0.0050%, and the mass fraction of N is controlled to be smaller than or equal to 0.0030%. The produced flux-cored wire steel is good in performance and wide in application range, the tensile strength is over 325 MPa, the yield strength is over 252 MPa, the production process cost of the steel strip is low, and the production stability is high.