Dolphin was downgraded to a tropical storm after making landfall, but officials continued to warn of heavy rainfall, severe flooding and possible landslides through Wednesday as the system moves north.
Before reaching China, authorities had issued their highest-level red alert for the storm, describing Dolphin as the strongest typhoon to hit the country this year.
According to meteorological authorities, the storm had maximum wind speeds of around 150 kilometres per hour when it first made landfall near Yuhuan in Zhejiang province at around 5:30pm local time on Sunday. It made a second landfall in the city of Wenzhou about an hour later.
Heavy rainfall has been forecast across several provinces, including Shandong, Henan, Hubei, Anhui, Jiangsu and Zhejiang, as well as Shanghai.
Hundreds of thousands evacuated in Zhejiang
Authorities in Zhejiang have carried out some of the largest evacuations as the storm approached.
Wenzhou officials relocated around 900,000 residents and opened more than 1,000 emergency shelters. Another 390,000 people were evacuated from their homes in Taizhou.
Forecasters said some parts of Zhejiang could receive between 250mm and 500mm of rain over the coming days.
In Hangzhou, the provincial capital, authorities waived parking fees in public parking areas to allow residents to move their vehicles to safer locations and seek shelter from strong winds and flooding.
Several tourist attractions have also been closed, including parts of Disneyland and Legoland, while viewing platforms along Shanghai's Bund have been shut.
State media footage showed flooded ground-floor businesses in Shanghai's former French Concession, while residents were seen walking through waterlogged streets.
Child reported missing
Chinese state media reported that a nine-year-old boy from Wenling in Zhejiang was missing after apparently being swept into the sea. Officials had not reported any deaths in China at the time of the reports.
In the coastal province of Fujian, authorities suspended dozens of passenger ferry routes and halted more than 100 offshore construction projects as a precaution.
China's state broadcaster CCTV reported that Dolphin travelled around 6,000 kilometres before making landfall in China, giving it a lifespan more than three times that of an average typhoon. The broadcaster also described the storm as having an unusually large circulation and intense rainfall capacity.
Storm also affects Philippines and Japan
Dolphin caused heavy rain in the Philippines, parts of northern Taiwan and Japan's Okinawa region before reaching China.
In the Philippines, eight people were reported dead as a result of heavy monsoon rains associated with Dolphin and other storms earlier in the week. More than 7,000 people were sheltering in evacuation centres across the country.
In Okinawa, five elderly people suffered non-life-threatening injuries, with three reportedly falling because of strong winds. Meanwhile, Hong Kong recorded a temperature of 36.9°C on Sunday as the typhoon pushed warm air across the city.
Authorities warn against misinformation
The storm has also triggered a wave of misinformation online in China. State media reported that two people had been detained over allegedly misleading content related to the typhoon.
One of them, a 60-year-old man, reportedly used artificial intelligence to create a fake video claiming that a person had fallen from a building in Shanghai during the storm.
Another man, aged 32, allegedly edited storm footage posted by other social media users in a way authorities considered misleading.
Typhoon season in the western Pacific generally runs from May to October. Experts have warned that storms can become particularly intense under certain climate conditions, increasing the risk of extreme rainfall, flooding and strong winds.
