Disclosed in the present disclosure are a data transmission method, a device, a system and a storage medium, belonging to the technical field of wireless communication. The method includes: determining, after receiving an uplink grant sent by a base station, a target level of quality of service, wherein the target level of quality of service is a level of quality of service of data scheduled by the uplink grant; acquiring target uplink data from uplink data to be sent, a level of quality of service of the target uplink data being consistent with the target level of quality of service; and sending the target uplink data through an uplink resource indicated by the uplink grant. The data transmission method provided by the embodiment of the present disclosure can ensure the efficiency of uplink data transmission.