The invention discloses a self-propelled multifunctional tunnel construction vehicle body, a trolley and a construction method, and is suitable for newly excavated tunnel support waterproof cloth andreinforcing steel bar forming cloth, the support time can be shortened to a maximum extent, and the support precision and quality are improved. The trolley comprises a trolley body, the trolley body comprises two parallel longitudinal beams and a plurality of trolley frames evenly arranged on the two longitudinal beams, every two adjacent trolley frames are further fixedly connected through a supporting device, the outer contour of each trolley frame is provided with a material distribution rail, and chains are welded to the material distribution rails. Annular reinforcing steel bar forming and traction distributing devices are arranged on the distributing rails of the trolley body, a reinforcing steel bar positioning and ejecting device is arranged between the reinforcing steel bar positioning and ejecting rails of every two adjacent trolley frames, and a reinforcing steel bar positioning and ejecting device is further arranged on each trolley frame.