The invention discloses a magnetic copper-nickel-iron-cobalt alloy thin strip and a preparation method therefor and relates to a copper base alloy in which cobalt is a secondary major ingredient. The general formula of the elemental composition of the magnetic copper-nickel-iron-cobalt alloy thin strip is CuxNiyFezCow; the preparation method of the thin strip comprises the steps of changing the proportioning of the composition of a magnetic copper-nickel-iron-cobalt alloy and adopting a melt-spun preparation method to prepare the magnetic copper-nickel-iron-cobalt alloy thin strip with better magnetism and composition uniformity, so as to overcome the problems of a copper-nickel-iron alloy of an existing elemental composition that the magnetism needs to be improved while a cast ingot has serious segregation, and the defect that the existing copper-nickel-iron alloy is not suitable for hot working is also overcome.