The utility model discloses a porcelain post insulator's electrification appearance of detecting a flaw aims at providing a convenient to use's porcelain post insulator's electrification appearance of detecting a flaw. It includes the casing to and emitter component and receiver subassembly, set up first mounting hole, second mounting hole on the casing, emitter component includes first fixed cover, the fixed first rubber sleeve of suit in first fixed cover, the fixed first guide pin bushing of suit in first rubber sleeve, clearance fit inserts in the first guide pin bushing, and stretch into the first guide arm in the casing, the spiro union is located the first nut of casing one end in first guide arm, fixed mounting is in the first barrel of the first guide arm other end, the reset spring of suit on first guide arm, fixed mounting is in the first section of thick bamboo cap of first barrel tip, wear to locate the emitting probe on the first section of thick bamboo cap, be located first barrel, screw rod with the emitting probe spiro union, the nylon cover of suit on the screw rod, the piezoelectric ceramic ring that the suit was sheathe in nylon, and twist the fastening nut on the screw rod soon.