The invention discloses a pneumatic type coupling system for preparing large remolded clay and performing one-dimensional consolidation test, which can be used for preparing a large-size cylindrical sample or hollow cylindrical sample of remolded clay in geotechnical engineering, and also can be used for performing one-dimensional consolidation test of a large clay sample. The pneumatic type coupling system comprises a displacement measuring system, a combined pressure cavity, a pore-pressure measuring system, a discharged-water volume measuring system, a pneumatic loading system and an axial tightening member. The pneumatic type coupling system disclosed by the invention has the advantages that the loading is carried out by a pneumatic mode, the pressurization is stable, uniform, measurable and controllable, the loading pressure can be more than 1.6MPa and the defect of difficult application of high pressure in weight loading is effectively overcome; a vertical metal permeable stone is embedded into a rigid and transparent sleeve to form a vertical water discharging channel, so that the defects of single water discharging channel and slow consolidation speed of traditional consolidation equipment are overcome; the pressure cavity of the pneumatic type coupling system is the rigid and transparent sleeve, so that the pneumatic type coupling system has visibility and overcomes the defect of invisibility of a traditional consolidometer.