The present disclosure provides a method and a device in a User Equipment (UE) and a base station used for wireless communications. The UE receives Q1 indication information groups, which correspond to Q1 time slices respectively; then the UE receives Q2 reference signals respectively in Q2 time slices of a first frequency sub-band, and transmits first information; wherein a channel measurement for the Q2 reference signals is used to generate the first information. The present disclosure simplifies the process of channel detection on unlicensed spectrum by limiting the channel measurement for generating the first information in the Q2 time slices, and improves the flexibility of the base station to configure multiple reference signal combinations, so as to optimize the process of beam management on the unlicensed spectrum and improve the overall transmission efficiency and performance of the system.