In recent years

accidents of breakage or breaking of porcelain post insulator due to their mechanical strength often occur. The traditional detection methods should require power off and the maintenance persons be working in high area

which is time consuming. In this paper

a detection method based on acoustic vibration technology is suggested

in terms of the modal natural frequency of post insulator to determine whether there are flaws in its ceramic column. Convenience is another major characteristic of this method. Based on the pre-test scheduled inspection of a 220 kV substation in Yunnan Province

it demonstrates the feasibility of using such vibro-acoustic detection method.