In bridge construction, due to the influence of the blocked time in the construction process, the general river management requires to minimize the blocked time, so higher requirements are put forward for the lifting speed, and the instantaneous speed reaches 30mm/s. In the past, the large end of the piston of the lifting jack is guided by the buckle copper ring, and the structure of both sides is sealed by the gray ring can not meet the requirements of high speed lifting. Taking the lifting jack used in cable-carried crane of Qingcaobei Yangtze River Bridge in Chongqing as an example, this paper introduces the sealing structure of 1 channel Glay ring seal + phenolic cloth guide belt to meet the requirements of high speed lifting.