A method and a device for multi-antenna transmission in a user equipment and a base station are disclosed in the present disclosure. The user equipment first receives a first signaling, receives a first wireless signal, and transmits first information. K antenna port groups are used to transmit the first wireless signal. The first signaling is used to determine the K antenna port groups. The K antenna port groups respectively correspond to K channel quality values. K1 antenna port groups of the K antenna port groups correspond to K1 channel quality values of the K channel quality values. The K1 is a positive integer less than or equal to the K. A first proportional sequence corresponds to a ratio(ratios) among the K1 channel quality values. The first information is used to determine the K1 antenna port groups and the first proportional sequence.