The invention discloses an adjustable cargo trailer shock absorption and supporting structure. The adjustable cargo trailer shock absorption and supporting structure uses a cross beam structure and a middle beam structure for bearing and supporting a trailer plate; the outer ends of a front trailer wheel adjusting main supporting arm and a rear trailer wheel adjusting main supporting arm are correspondingly connected with a front trailer wheel and a rear trailer wheel; and the inner ends of the front trailer wheel adjusting main supporting arm and the rear trailer wheel adjusting main supporting arm can keep being rotationally and movably connected with adjusting bearing brackets correspondingly. By controlling the telescoping movement of a front wheel adjusting cylinder and a rear wheel adjusting cylinder, the front trailer wheel adjusting main supporting arm and the rear trailer wheel adjusting main supporting arm can be controlled to rotate on the adjusting bearing brackets, and the effects of adjusting the distance between the front trailer wheel and the rear trailer wheel and also adjusting the height between the trailer plate and the ground are achieved; at the same time, as the inner ends of the front trailer wheel adjusting main supporting arm and the rear trailer wheel adjusting main supporting arm can keep being rotationally and movably connected with the adjusting bearing brackets correspondingly, compared with an existing trailer supporting structure, the shock absorption performance is enhanced, and a shock absorption system does not need to be additionally arranged.