A jet pump measuring pipe repair method that repairs a ruptured part of a measuring pipe horizontally installed to a lower portion of a jet pump provided in reactor water inside a reactor pressure vessel. The repair method includes: fixing a support member to the jet pump near the measuring pipe left remained; mounting, after the support member fixing, a measuring pipe connector provided with a pipe-repairing pipe having both ends over which connecting pipes are fitted, respectively, to the support member; connecting, after the connector mounting, the remaining measuring pipe and connecting pipe using the measuring pipe connector.