The invention belongs to the technical field of alloy tool steel, and particularly relates to cold-rolled strip steel for a duplex metal saw blade backing material and a manufacturing method thereof.The manufacturing method of the cold-rolled strip steel for the duplex metal saw blade backing material comprises the following step that a hot rolled steel roll is subjected to softening annealing, acid pickling, full hydrogen hood type furnace spheroidizing annealing, single-rack reversible cold rolling mill cold rolling, polishing unit abrasive cloth polishing, full hydrogen hood type furnace annealing and leveling to obtain a finished product. According to the cold-rolled strip steel and the manufacturing method, based on general steel production equipment, the problems that surface decarburization and surface layer boundary oxidation exist, annealed and reduced sponge iron is difficult to pickle, and the straightness control is poor are solved, and high-quality low-cost production isachieved; and according to the cold-rolled strip steel for the duplex metal saw blade backing material, the average grain size of ferrite is 4 to 4.5 micrometers, the size of cementite is 0.3 micrometer or less, the spheroidization rate is 95% or above, the average hardness is 256-280 HV, no semi-decarburized layer exists, no grain boundary oxide layer exists, and the flatness in the width direction does not exceed 0.5% of the width.