The utility model relates to a joint device for a stainless steel thin pipe, which is composed of a stainless steel thin pipe and a standard part joint. The utility model is characterized in that the end of the stainless steel thin pipe is provided with a flange, and the pipe wall and the axial direction of the thin pipe form 90 DEG; the thin pipe is provided with a conical sleeve ring and a locking nut, and the conical sleeve ring and the locking nut can move in the axial direction along the thin pipe; the standard part joint is provided with an inner and an outer sealing rings and a joint screw. The utility model has the advantages of simple structure, easy production and operation and low cost (three yuan per meter) and creates favorable condition for the stainless steel thin pipe to take the place of the existing galvanized pipe to improve tap water quality.