A user equipment, a control method thereof and a network side device are provided in the present disclosure. The control method includes: indicating configuration information of a subband to be configured to a user equipment via a common control channel of a basic subband, such that the user equipment can use the subband to be configured according to the configuration information, wherein the basic subband is a subband to which the user equipment has access, and the subband to be configured comprises any subband within a bandwidth resource. The above method can support the flexibility of subband configuration.