A method for feeding back channel state information, comprising: a piece of User Equipment, UE, determining channel state information which comprises a first-type Precoding Matrix Index, PMI, and a second-type PMI according to indication information, wherein the first-type PMI is used for indicating an index of one first precoding matrix in a first precoding codebook, and each first precoding matrix is used for mapping channel information of one wideband and/or long-term channel; and the second-type PMI is used for indicating an index of one second precoding matrix in a second precoding codebook, and each second precoding matrix is used for mapping channel information of one subband and/or short-term channel; and the UE feeding back the first-type PMI in a Physical Uplink Control Channel, PUCCH, periodically and feeding back the second-type PMI in a Physical Uplink Shared Channel, PUSCH, periodically or non-periodically; or, feeding back the first-type PMI and the second-type PMI in the PUCCH, wherein a precoding matrix W is a function of the first precoding matrix indicated by the first-type PMI and the second precoding matrix indicated by the second-type PMI; and characterized in that feeding back the first-type PMI and the second-type PMI in the PUCCH further comprises: the UE feeding back the first-type PMI in the PUCCH, and feeding back the second-type PMI in the PUCCH in a mode of single UE-selected subband PMI, or a mode of single UE-selected subband CQI and single UE-selected subband PMI, or a mode of CQI and PMI of a single Bandwidth Part, BP. a piece of User Equipment, UE, determining channel state information which comprises a first-type Precoding Matrix Index, PMI, and a second-type PMI according to indication information, wherein the first-type PMI is used for indicating an index of one first precoding matrix in a first precoding codebook, and each first precoding matrix is used for mapping channel information of one wideband and/or long-term channel; and the second-type PMI is used for indicating an index of one second precoding matrix in a second precoding codebook, and each second precoding matrix is used for mapping channel information of one subband and/or short-term channel; and the UE feeding back the first-type PMI in a Physical Uplink Control Channel, PUCCH, periodically and feeding back the second-type PMI in a Physical Uplink Shared Channel, PUSCH, periodically or non-periodically; or, feeding back the first-type PMI and the second-type PMI in the PUCCH, wherein a precoding matrix W is a function of the first precoding matrix indicated by the first-type PMI and the second precoding matrix indicated by the second-type PMI; and characterized in that feeding back the first-type PMI and the second-type PMI in the PUCCH further comprises: the UE feeding back the first-type PMI in the PUCCH, and feeding back the second-type PMI in the PUCCH in a mode of single UE-selected subband PMI, or a mode of single UE-selected subband CQI and single UE-selected subband PMI, or a mode of CQI and PMI of a single Bandwidth Part, BP. the UE feeding back the first-type PMI in the PUCCH, and feeding back the second-type PMI in the PUCCH in a mode of single UE-selected subband PMI, or a mode of single UE-selected subband CQI and single UE-selected subband PMI, or a mode of CQI and PMI of a single Bandwidth Part, BP.