Typhoon Mangkhut is lashing China's most populous province, bringing winds of up to 100 mph (162 kph).
Guangdong is on its highest alert for the storm, which swept in from Hong Kong where it swayed skyscrapers and blew out windows.
The death toll from the Philippines meanwhile jumped from 30 to 49, with most of the victims claimed in landslides caused by heavy rain.
Mangkhut is considered the strongest storm of 2018, according to BBC.
Typhoon Mangkhut made landfall on the Chinese coast near Jiangmen city on Sunday afternoon local time, state media reported.
Thousands of people have been evacuated from Guangdong, and authorities there issued their highest warning level, a red alert.
In Hong Kong, authorities also issued their maximum alert, with residents warned to stay indoors to avoid flying debris. Winds there reportedly reached more than 110 mph (117 kph).
Officials put the number of injured at 111 but the territory avoided a direct hit.
Water levels surged by almost 3.5 metres (12 ft) in places and live fish were washed on to the streets.
Most shops and public services were shut, and more than 800 flights have been cancelled at Hong Kong International Airport - affecting more than 100,000 passengers.