The invention provides a cloud service system for home-based care for the aged, which comprises a city big data center consisting of a data acquiring unit and a city-area narrow-band internet-of-things unit, a care service sub-unit, a calling center sub-unit, a pre-warning prompting and aiding sub-unit, a government data sharing sub-unit, a cloud data analyzing engine unit. The data acquiring unit comprises an intelligent smoke sensor, a water consumption information sensor, an SOS emergency speaking module, a door and passage human body sensor, and a biological characteristics sensor. The data acquiring unit is arranged at home; and the wireless data outputted from the data acquiring unit act on the city-area narrow-band internet-of-things unit; and the city-area narrow-band internet-of-things unit, is connected with the cloud data analyzing engine unit through the city-area narrow-band internet-of-things; the government data sharing sub-unit and the cloud data analyzing engine unit are connected through a network. The care service, the calling center, the pre-warning prompting and aiding, the government data sharing sub-units are software installed in the computer of the engine unit. With the system, it is possible to provide assistance and aid to the aged and provide data for relevant government departments.