The typhoon landed in the coastal areas of Dongshan county of Fujian at around 5.20 a.m. and Raoping County of Guangdong at about 6.45 a.m., bringing gales of up to 20 and 18 meters per second near its centre, respectively, Xinhua news agency reported.
Haikui is expected to move westward at 10 to 15 km per hour and gradually weaken, according to the Guangdong meteorological observatory.
The typhoon made landfall in Taiwan on Sunday.
According to disaster management authorities in Guangdong, as of 12 noon on Monday, evacuation tasks had been completed in all the sea areas east of Huizhou city, with 27,897 fishing boats taking shelter in the harbour, as well as 2,139 fishing personnel, 453 offshore wind power workers and 149 marine ranching personnel all landing to take shelter.
All 25 coastal scenic spots were closed.
Additionally, 515 trains in Guangdong and 23 sea passenger routes east of Huizhou had been suspended due to flood and typhoon prevention.
Classes were also suspended in the cities of Shantou and Chaozhou.
Separately,the National Meteorological Centre issued a yellow alert for rainstorms on Tuesday as heavy downpours were expected to lash parts of south and east China.
From 8 a.m. Tuesday to 8 a.m. Wednesday, heavy downpours and rainstorms are forecast to hit parts of Fujian, Guangdong, Jiangxi, Zhejiang and Taiwan Island, according to the centre.
Some areas of these regions are expected to experience heavy rainfall, with maximum hourly precipitation exceeding 70 millimeters, accompanied by strong convective weather, such as thunderstorms and gales.
The centre has advised local governments to prepare for rainstorms.
Traffic management departments should implement proper traffic control on road sections hit by heavy downpours, and guide traffic on waterlogged sections.
It has also suggested disconnecting at-risk outdoor power supplies, suspending outdoor operations in open areas, and transferring people from dangerous areas to safer places.