A small data transmission method, configured for a User Equipment (UE) to transceive a small data from a control node in a wireless network without establishing a Radio Resource Control (RRC) connection, and the method includes but not limited to the step of: monitoring a paging opportunity (PO) sub frame in a paging frame in an idle mode; when an identifier in the PO sub frame corresponding to the UE is detected, receiving a paging message corresponding to the PO sub frame; and analyzing the paging message, and when the paging message includes a small data indicator, extracting a data from an indicating address, in which the data is the small data.