Shimizu says the Ocean Spiral would cost three trillion yen ($25 billion), and all the technology could be in place by 2030.
It is the third such project unveiled by the company after a floating metropolis and solar power ring around the moon.
“The company in cooperation with many organizations has spent two years to design the project working with technologies we think will be plausible in the future,” said a Shimizu spokesman.
In 2012, another Japanese construction firm, Obayashi Corp, claimed it could execute an out-of-this-world plan to put tourists in space within 40 years by building an elevator that stretches a quarter of the way to the moon.
Obayashi claimed it could use carbon nanotube technology, which is more than 20 times stronger than steel, to build a lift shaft 96,000 kilometers above the Earth.