The invention belongs to the technical field of repair and maintenance of bridges, and particularly relates to a door connected bridge maintenance car which comprises an upper lateral combination (1), wheeled walking cars (2), beams (3), vertical truss mechanisms (4), rotating devices (5), bottom detection platforms (6), jacking oil cylinders (7), walking mechanism longitudinal beams (8), vertical truss longitudinal beams (9), telescopic frames (12), surrounding frames (13), connecting oil cylinders (15), frame longitudinal beams (16) and chain wheel driving devices (17). According to the door connected bridge maintenance car, walking cars of two sides are connected with the upper lateral combination through flanges to form a portal frame structure, the bridge maintenance car can stably walk on a bridge floor by the aid of telescopic butting technique of the bottom detection platforms and collision avoidance technique of bridge side barriers, the maintenance car can rapidly avoid the barriers of bridge sides and bridge piers, lanes cannot be occupied, bridge traffic cannot be affected, the maintenance car is high in applicability and simple to operate, and working efficiency of the maintenance car is improved.