The invention discloses a tunnel form-spraying concrete support construction device and method. The tunnel form-spraying concrete support construction device includes a steel support structure for supporting and fixing the whole device, the steel support structure is anchored on the inner wall of a tunnel through anchoring rods, formworks for form-spraying concrete forming is fixedly installed onthe steel support structure, and the formworks are successively installed from bottom to top along the interior of the tunnel; the formworks are detachably connected with the steel support structure through steel form fixtures; and a bottom blocking formwork for blocking the bottom of the formwork is arranged between the formwork located at the lowest layer and the inner wall of the tunnel, and end sealing formworks for sealing openings in the side end faces of the formworks are arranged between the side end faces of the formworks and the inner wall of the tunnel. According to the tunnel form-spraying concrete support construction device, the structure is simple, use is convenient, the quality is controllable, and the traffic requirements are met, the tunnel form-spraying concrete construction environment can be effectively improved, the form-spraying efficiency and quality are improved, and the construction cost is lowered.