Device for solving water leakage of free roller of continuous casting machine and using method of device

The invention discloses a device for solving the water leakage problem of a free roller of a continuous casting machine and a using method of the device. An original three-piece combined rigid sealing structure is replaced by a flexible connecting piece. The flexible sealing piece comprises a rigid straight section piece, a corrugated pipe, an O-shaped sealing ring and a guide ring. The rigid straight section piece and the corrugated pipe are welded into a whole; the rigid straight section piece and the inner hole of the free roller are sealed by an O-shaped ring; the O-shaped sealing ring and the guide ring are mounted in a groove of the rigid straight section; due to the fact that the flexible corrugated pipe has the characteristics of axial compensation, transverse compensation and angle compensation, alternating stress can be effectively absorbed, it is guaranteed that rigid straight sections at the two ends do not deform greatly when the free roller bears repeated intermittent loads and vibration, sealin