Weak magnetic internal detection device for long oil and gas transmission pipeline

The invention discloses a weak magnetic internal detection device for a long oil and gas transmission pipeline. The weak magnetic internal detection device for the long oil and gas transmission pipeline comprises a power part and a detection part, wherein the power part is flexibly connected with the detection part through a universal joint, and comprises a power joint and power leather cups; the power leather cups are arranged at two ends of the power joint and are adaptive with the inner wall of an oil and gas pipeline; a chamber is formed in the power joint; an energy storage device is arranged in the chamber; the detection part comprises a measurement joint, a weak magnetic detection assembly, a detection position recording unit and a positioning device; one end of the measurement joint is flexibly connected with one end of the power joint through the universal joint; the detection position recording unit and the weak magnetic detection assembly are arranged on the measurement joint; the positioning devic