The invention discloses an electric automobile overhaul cover plate assembly which comprises a rear floor front crossbeam, a pair of rear floor longitudinal beams and a rear floor rear crossbeam. The pair of rear floor longitudinal beams are arranged between the rear floor front crossbeam and the rear floor rear crossbeam to form a frame. A rear floor middle crossbeam is arranged between the rear floor front crossbeam and the rear floor rear crossbeam. A detachable front overhaul cover plate is arranged at the position, between the rear floor front crossbeam and the rear floor middle crossbeam, in the frame. A detachable rear overhaul cover plate is arranged at the position, between the rear floor middle crossbeam and the rear floor rear crossbeam, in the frame. Both the front overhaul cover plate and the rear overhaul cover plate are each of an aluminum plate structure, and reinforcing ribs are arranged on the aluminum plate structures. The electric automobile overhaul cover plate assembly is reasonable in structural design, a hollow aluminum profile structure is adopted in a supporting beam, a rear floor detachably forms the corresponding overhaul cover plate which is of the aluminum plate structure, the weight is small, the structural strength is large, lightweight of the electric automobile is facilitated, the cruising mileage can be effectively increased, and the use cost is reduced.