A Chinese worker who tended to his injured colleagues following a deadly earthquake and then got lost in the mountains in the province of Sichuan has been rescued 17 days later.

The 6.8-magnitude quake struck the southwestern province earlier this month, killing at least 93 people and forcing thousands to be resettled into temporary camps.

Gan Yu, an employee at Sichuan's Wandong hydropower plant, was found alive but injured on Wednesday by a local villager, China National Radio (CNR) said, calling the rescue a "miracle of life".

Gan was on duty with his co-worker Luo Yong on September 5 when the quake hit, and the pair stayed behind to give first aid to injured colleagues and prevent flooding by releasing water from the dam.

They attempted to leave the remote power station, walking for around 20 kilometres. But Gan – who is severely short-sighted – had lost his glasses during the quake and struggled to navigate the mountainous terrain, CNR said.

The two men tried desperately to signal distant rescuers for help. "We took our clothes off, strung them on tree branches and waved them around," Luo told CNR.

They eventually decided that Gan should stay put while Luo went looking for assistance.

Luo helped make Gan a bed of moss and bamboo leaves and left him some wild fruit and bamboo shoots to eat before the two men separated.

Luo was found by rescuers on September 8 after using a fire to attract a helicopter's attention, but by the time Gan's temporary shelter was discovered on September 11, he had disappeared.

Finding only discarded clothing and footprints, the rescuers feared Gan had succumbed to hypothermia.

Earlier this week, local farmer Ni Taigao returned to his village at the foot of the mountain where the power plant is located and heard about the hunt for Gan.

The villager put his local knowledge to use and joined the search on Wednesday morning.

After just two hours of trekking, he heard Gan's faint cries and soon spotted him lying under some trees. It took the other rescuers several more hours to reach Gan, who was flown on Wednesday to a nearby hospital where doctors found he had suffered multiple bone fractures, according to broadcaster CCTV.

Footage from CCTV showed a shaken-looking, gaunt Gan confirming his name and gingerly eating a snack offered by rescuers. (AFP)