The U-shaped groove at the end of the compression type stainless steel pipe fitting is equipped with a special rubber sealing ring. During installation, the stainless steel water pipe is inserted into the socket of the compression type stainless steel pipe fitting to the positioning step position. Special compression tools are used to perform compression operations on the U-shaped groove and the compression parts on one or both sides of the U-shaped groove simultaneously. After being squeezed, the rubber sealing ring plays a sealing role, causing both the stainless steel pipe fittings and the stainless steel water pipes to shrink and deform at the clamping position (forming a hexagonal shape on the profile), playing a positioning and fixing role, thus effectively achieving the connection of the stainless steel pipe fittings.