The temperature of sliding bearing bushings is one of the most important monitoring parameters for the operation of large rotating equipment,but the oil leakage in the cable part of its temperature measuring element is a pain point in on-site equipment management.This article calculates the cavity ratio of the temperature measuring element cable structure by decomposing it,confirms that the siphon effect is the main cause of cable oil leakage,and provides three blocking schemes.After comparison and practical verification,a cost-effective and effective solution for instrument cable oil leakage is obtained.