Disclosed are an enhanced carrier aggregation (CA) scheduling method and device in a user equipment (UE) and a base station, the method comprising: in a first step, a UE receives a high-level signaling determining K sets of configuration information, the configuration information comprising {a first index, a second index, a third index, and working frequency band information}; in a second step, the UE receives, at a first service cell, a first signaling, the first signaling comprising a fourth index and scheduling information; and in a third step, the UE determines a second service cell according to first configuration information and the fourth index in the first signaling. The present disclosure reduces the number of bits in downlink control information (DCI), thus conserving an air interface resource, or improving the receiving performance of the DCI. Furthermore, the present disclosure instructs the third index not to modify the number of bits of the DCI by utilizing an existing carrier indicator field (CIF), thus maximally maintaining compatibility with an existing system.