The embodiment of the invention discloses a data transmission method, a data receiving method, data transmission equipment and data receiving equipment, which relate to the technical field of wireless communication and are used for saving the wireless air interface resources and node signaling resources of a system. In the methods and the equipment, after receiving small data required to be transmitted to a terminal in an idle state, core network equipment transmits a paging message carrying small data indication information to the terminal; after receiving the paging message carrying the small data indication information, the terminal responds to the paging message by an uplink non-access stratum (NAS) message rather than initiating a service request process; and after receiving the uplink NAS message, the core network equipment transmits the small data to the terminal by a downlink NAS message. By the methods and the equipment, system resources can be saved.