Embodiments of the present invention disclose a method for feeding back uplink control information in a downlink MIMO mode and a user equipment, which are used to implement that a UE feeds back control information to a base station, are applicable to a precoding weight set restriction application scenario, and reduce transmit power of the UE while ensuring HS-DPCCH receive performance of the base station. The method provided by the embodiments of the present invention includes: generating, by a UE, 1-bit precoding control indicator (PCI) information; generating, by the UE, channel quality indicator (CQI) information; performing, by the UE, joint encoding on the PCI information and the CQI information, to obtain a joint encoding result; and feeding back, by the UE, the joint encoding result to a base station through an uplink high speed dedicated physical control channel (HS-DPCCH).