This is the shocking moment a barber howled in agony after being zapped by a massive electric shock while trying to fix a plugged-in hairdryer.

CCTV footage shows the hairdresser using a screwdriver to fiddle with the hairdryer's controls inside a salon in Dalian, Liaoning, China.

Suddenly, he yelps in pain and begins to convulse as he touches a live wire.

With his face contorted in agony, he drops to his knees, unable to release the blow dryer.

He is only rescued when quick-thinking colleague Mr Dong runs over and switches off the power at the mains.

The worker then collapses onto the floor, rolling around and gasping in relief as he slowly recovers.

Local media reported that he suffered an injury to his hand but was otherwise unharmed by the electric shock on June 12.