The invention discloses an efficient and energy-saving aerosol can capping system which comprises a cap conveyor and a capping device. The capping device comprises a rotary shaft, an upper turntable, a lower turntable and a press-fit device, a plurality of cap clamping openings are formed in the upper turntable, can body clamping openings corresponding to the cap clamping openings are formed in the lower turntable, the cap conveyor comprises a platform, a first side plate, a second side plate and a turntable, the first side plate, the second side plate and the turntable are arranged on the platform, a first end plate is arranged at the end, which is close to the turntable, of the first side plate, a second end plate is arranged at the end, which is close to the turntable, of the second side plate, a discharge channel is formed between the first end plate and the second end plate, single rows of caps can pass through the discharge channel, and a distribution barrier which is positioned on the upper side of the turntable is mounted on the platform. The efficient and energy-saving aerosol can capping system has the advantages that the caps can be automatically conveyed to cap pressing points, the conveyed caps are clamped by the cap clamping openings, the upper ends of conveyed can bodies are clamped by the cap clamping openings, and the lower ends of the conveyed can bodies are clamped by the can body clamping openings, so that deviation among the caps and the can bodies can be assuredly prevented, the cap pressing efficiency can be improved, the efficient and energy-saving capping system is high in efficiency, and energy can be saved.