The invention relates to a method for reinforcement repair of a metal pipeline with the defect, which is particularly suitable for on-site operations under the condition of continuous transmission of the pipeline. The method is characterized in that: after the surface of a pipe body is treated by using sand blast (recommended) or an electric angle grinder, the defect 2 is filled and leveled up by hot spraying metal alloy, and the surface of the integral circle of the pipe body 1 is sprayed to form a metal alloy basement layer 3, wherein the metal alloy basement layer has the excellent compression strength; a fiber resin composite 4 formed by fibers and an epoxy bonder is wound on the basement layer, the cured fiber resin composite has the high tensile strength and elastic modulus, so the fiber resin composite limits the radial dilatational strain at the defect, and reduces the stretching stress and stretching strain at the defect through the metal alloy basement layer to realize the reinforcement repair on the defect of the pipeline.