The application provides a
data transmission method and device, equipment and a storage medium, which are applied to an access and
mobility management function (AMF), and include the following steps: receiving downlink data directly issued by a network
exposure function (NEF); when it is determined that a current state of a UE is unreachable, it is determined whether the AMF is allowed to cache the downlink data according to a caching instruction of the NEF; and when it is determined that the AMF is allowed to cache the downlink data, the downlink data is cached, so that the related signaling of the
core network is reduced, and the time
delay of sending
Internet of Things data to the UE is reduced.