The invention relates to the technical field of household supplies, in particular to a manufacturing method of a window lock part of a sliding window. The method includes: a first lock body and a second lock body are made of aluminum alloy materials, the first lock body is provided with a circular through hole, and the second lock body is provided with an elongated hole; a lock rod, a retaining block and a limit part jointly form a lock cylinder, and the lock cylinder is made of carbon steel and produced through a conventional forging process; each of the three parts of the lock cylinder is placed in a electroplating tank and electroplated with a protecting layer; after the electroplating, deionized water is used for cleaning, and drying is performed, wherein tank liquid comprises 17 parts of amino resin, 6 parts of acrylic emulsion, 3 parts of flow promoter and the like; the lock rod is welded to the limit part, the lock rod is inserted from the through holes, and the retaining block is welded to the other end of the lock rod; the first lock body and the second lock body are mounted on a first inner window frame and a second inner window frame. The electroplating process is added to the manufacturing method, so that the wear resistance and corrosion resistance of the window lock part can be increased to a certain degree.