China will move nearly 10,000 people to make way for the world's largest radio telescope which promises to help humanity search for alien life, state media reports.

The 500-metre Aperture Spherical Radio Telescope (FAST), nestled between hills in the south-western province of Guizhou, is due to start operation this year.

Provincial officials have vowed to relocate 9,110 residents living within 5 kilometres of the listening device by September.

The relocations will "create a sound electromagnetic wave environment", regional official Li Yuecheng said.

People standing at the site of the telescope while under construction. ( AFP, file )

Residents will receive 12,000 yuan ($2,575) in subsidies for their troubles, with some getting extra support for housing.

FAST, built at a cost of 1.2 billion yuan, will dwarf the Arecibo Observatory in Puerto Rico as the world's largest radio telescope, which is some 300 metres in diameter.

Wu Xiangping, director-general of the Chinese Astronomical Society, said the telescope's high level of sensitivity "will help us to search for intelligent life outside of the galaxy".

In the past China has relocated hundreds of thousands of people to make way for large infrastructure projects such as dams and canals.

Many complain of poor compensation.

The area surrounding the telescope is remote and relatively poor.

Media reports earlier said the location was chosen because there are no major towns nearby.

As well as upping investment in astronomy, Beijing is accelerating its multi-billion-dollar space exploration program, with plans for a permanent orbiting station by 2020 and eventually a manned mission to the moon.

AFP