A man who was bushwalking had to be winched out of a far north Queensland national park after being bitten by a snake.

A bushwalker has been winched into a rescue helicopter after being bitten by a snake in far north Queensland.

The 35-year-old man is being treated in Cairns Hospital.

He was rescued from a track in the Wooroonooran National Park, 20km south of Cairns, early on Thursday, authorities said.

The type of snake is unknown.