The invention provides a stainless-steel-lined composite grooved pipe fitting. The stainless-steel-lined composite grooved pipe fitting comprises an outer-layer groove malleable cast iron pipe fitting, a fixing body, a stainless steel lining and an end face flanging layer. The stainless steel lining is fixed to the inner wall of the outer-layer groove malleable cast iron pipe fitting through the fixing body, the end face flanging layer is arranged at the end of the outer-layer groove malleable cast iron pipe fitting, and the end of the end face flanging layer is fixedly connected with the end of the stainless steel lining. The technical problems that during connection of an existing stainless-steel-lined composite grooved pipe fitting, due to the fact that the end face and the lining are simultaneously located in medium water and the potential difference exists between different materials, galvanic corrosion is generated, the pipe fitting is corroded, and then drinking water is polluted are solved.