Composite telescopic vehicle-mounted connecting mechanism

The utility model discloses a composite telescopic vehicle-mounted connecting mechanism which comprises a main supporting arm, a first-stage telescopic arm and a second-stage telescopic arm. The main supporting arm is of a frame structure with a cross-shaped section and comprises a horizontal supporting arm and a vertical supporting arm, the horizontal supporting arm and the vertical supporting arm are hollow square tubes, the first-stage telescopic arm is of a frame structure with an E-shaped section, and the second-stage telescopic arm is of a frame structure with an E-shaped section. Comprising a horizontal fixed arm, a left vertical arm, a right vertical arm and a central vertical arm, wherein the left vertical arm and the right vertical arm are symmetrically arranged at two ends of the horizontal fixed arm; according to the connecting mechanism, multiple coupling mechanisms such as multi-direction linkage telescopic connection, overall hinge joint with a movable platform and an operation follow-up suppor