Disclosed is a system, central control device, an application device for the Internet of things and communication methods applied to the Internet of Things system. The Internet of Things includes the center control and a plurality of application devices, wherein the central control device includes: a central control unit configured to perform a central control function of the central control device under control of a first clock signal; an asynchronous communication unit configured to perform data communication between the central control device and a plurality of application devices in the Internet of Things by using an asynchronous circuit; a synchronous-asynchronous interface configured to perform data transmission between the central control unit and the asynchronous communication unit.