Presser foot for sandwich flat seaming and sandwich flat seaming process

The invention discloses a presser foot for sandwich flat seaming, and belongs to the technical field of sewing instruments. Comprising a base and a connecting rod seat connected with the flat seaming machine, a limiting barrier strip and a limiting check block are installed on the left side and the right side of the base respectively, a needle inlet hole allowing a flat seaming needle to penetrate through is formed in the middle of the base, a partition barrier strip parallel to the limiting barrier strip is arranged in the needle inlet hole, and a seaming receding groove is formed between the needle inlet hole and the partition barrier strip. A core wire limiting part is arranged at the bottom of the base at the front end of the needle inlet hole, a core guide hole allowing a core wire to penetrate through is formed in the core wire limiting part, and the core guide hole and the barrier strip are arranged on the same straight line; a core wire limiting groove parallel to the limiting barrier strip is formed