A clutch cap screwing device of a linear pump cap screwing machine comprises a rack front side plate, torque cap screwing components, rotating driving components, a centering linear driving adjusting mechanism, sliding seats, sliding guide rails and a rack rear side plate. The two sliding guide rails are horizontally and fixedly mounted on the rack front side plate and the rack rear side plate in parallel, the two sliding seats are mounted on the two sliding guide rails in a sleeved mode, the torque cap screwing components are mounted on the lower end faces of the sliding seats, the rotating driving components are mounted on the upper end faces of the sliding seats, the rotating driving components drive the torque cap screwing components, the centering linear driving adjusting mechanism is arranged between the rack front side plate and the rack rear side plate, and a driving motor of the centering linear driving adjusting mechanism is connected with the sliding seats. The clutch cap screwing device of the linear pump cap screwing machine solves the problem of manual cap screwing, a flow process of continuous linear cap screwing can be achieved, a great amount of man power is saved, cap screwing efficiency is high and is 100 times that of manual cap screwing, and the aesthetic standards of people for diversified bottle bodies are met.