Abstract: In actual work of horsepower tractors，most of the work such as hoisting system work devices，hydraulic output，steering and lubrication was controlled and executed by hydraulic system.Hydraulic pipe plays an important role in the hydraulic system as hydraulic energy transmission link.In this regard，sealing performance of hydraulic pipe connector determines reliability of hydraulic system.Through research and analysis of pipeline sealing method of the large tractor hydraulic system，effective hydraulic pipeline sealing measures were summarized to provide support for design and improvement of large tractor hydraulic system，and then to improve reliability of large tractors.