The provincial meteorological bureau says the typhoon was expected to be "the most powerful and destructive to land in Hainan in a decade."
Typhoon Sarika lashed China's southern resort island of Hainan on Tuesday, with torrential rain and winds of up to 162 kilometres per hour (100 mph) forcing authorities to evacuate almost half a million people and halt transport services.
Rail services were suspended on Monday and 250 flights were cancelled at the provincial capital Haikou's international airport, state news agency Xinhua said.
The provincial meteorological bureau expects losses from the typhoon to be "grave" as the storm was expected to be "the most powerful and destructive to land in Hainan in a decade," Xinhua said.
Nearly 500,000 people, including fishermen and residents in low-lying areas, have been evacuated, the report said.
Schools were shut in eight counties and tourist sites were closed to the public, it said.
Once the storm passes Hainan, which China likes to style as its answer to Hawaii or Bali, it will barrel into the southern Chinese region of Guangxi, state television added.
Typhoons are common at this time of year, picking up strength as they cross warm Pacific waters and bringing fierce winds and rain when they reach land.