The invention provides a lathe spindle center spraying cooling device which aims at solving the problem that when a digital controlled lathe is used for machining an inner hole of a part, cooling liquid carries out washing to the inside from the machining end of the part, and the washing direction is different from the swarf discharging direction of the part. The lathe spindle center spraying cooling device is characterized in that an oil cylinder is assembled at the back end of a lathe spindle, the two ends of a hollow pulling rod are connected with a hollow piston rod of the oil cylinder and a connecting rod in the center of a chuck respectively, the chuck is installed at the front end of the spindle through a bolt, a spraying nozzle is connected with the chuck through a bolt, all threaded rotary connecting parts are sealed by sealing rings, and a pipe connector is installed on the oil cylinder. Cooling water sequentially passes through the pipe connector, the oil cylinder, the pulling rod in the center of the spindle, the chuck and the spraying nozzle to be sprayed on the inner hole of the part. The lathe spindle center spraying cooling device has the advantages that the spraying direction of the cooling water is the same as the swarf discharging direction, and the swarf discharging efficiency is improved.