The invention relates to a thin wall tightening collector for metal tube that uses rotating nut to make the tube cause plastic deformation of contracting and block into the dent groove circle of the joint to achieve the aim of connecting tube tightly. The feature of the connector is that it is easy to connect and sealing is reliable, and the pulling proof force would be equal to the stretching resistance of the tube material. The advantage of the invention is that: first, it solves the problem of having not enough pulling proof force of the existing thin wall metal tube connector; second, it needs not to be preprocessed; third, it reforms the connection process of the tube. Thus, the invention is especially suited for connecting the thin wall metal tube that is bearing high pressure.