The invention discloses a locking oil cylinder structure with a stroke tail end buffered. The locking oil cylinder structure comprises an oil cylinder seat, a buffer valve sleeve, a buffer valve element, a piston and a spring, the oil cylinder seat is provided with an oil supply channel and an oil cylinder cavity, the buffer valve sleeve is arranged on the oil cylinder seat, the piston is located in the oil cylinder cavity, the buffer valve element is arranged in the buffer valve sleeve in a sliding and matching mode, the spring is arranged between one end of the buffer valve element and the buffer valve sleeve, the other end of the buffer valve element stretches into the oil cylinder cavity, a large-flow channel and a small-flow buffer channel which are used for supplying oil to the oil cylinder cavity are arranged between the oil supply channel and the oil cylinder cavity, the large-flow channel is arranged between the oil cylinder seat and the buffer valve element, and the small-flow buffer channel is arranged on the buffer valve element. When the piston reaches a certain stroke, the buffer valve element is matched with the oil cylinder seat under the action of the spring to plug the large-flow channel, and oil passes through the small-flow buffer channel from the oil supply channel and flows into the oil cylinder cavity. The locking oil cylinder structure can achieve the quick locking function, and has the buffer function in the later locking period, and therefore tool changing speed can be improved, and meanwhile the impact phenomenon is avoided.