The present invention provides a data transmission method, apparatus and system, which relate to the field of the wireless network technology. The data transmission method provided in the embodiment of the present invention includes: acquiring a downlink data packet sent to a terminal, in which the downlink data packet does not have a high layer protocol stack header; sending the downlink data packet to the terminal through an air interface; Through the present invention, the data amount in the air interface transmission is reduced to a great extent, the efficiency of air interface transmission is substantially enhanced, and the air interface resource is saved, thereby facilitating the enrichment and development of wireless services and satisfying the demands of users. The present invention is applicable to a scenario of air interface transmission in a wireless network.