High voltage porcelain post insulator is an important equipment of the power plant and substation in a power system.In recent years

the post insulator faults due to cracking often happen when the power grid is in operation

which endangers the safe operation of the power system.This paper takes "4.10 Shenzhen Blackout" as an example to verify the feasibility of the vibration detection method for detecting post insulator.Experiment is designed for detection of the intact and damaged post insulators in order to explore the regularity of vibration detection.The vibration detection method is compared with the traditional ultrasonic detection

and the result confirms the vibration detection method is both feasible and efficient.