The invention discloses a channel state information feedback and data transmission method and device. The method comprises the following steps: determining a first codebook at a base station side, wherein the first codebook is a set formed by pre-coding matrixes; determining the first codebook at a terminal side, wherein the first codebook is a set formed by the pre-coding matrixes; calculating channel state information according to the first codebook; feeding back the channel state information to the base station; and the base station side carrying out data transmission on the terminal, and in the data transmission process, using a part of or all of the pre-coding matrixes in the first codebook to process data to be transmitted on a resource allocated to the terminal. Through the device and method, the pre-coding matrixes required for open loop MIMO calculation can be determined, so that full space traversal can be prevented, system design and realization difficulty is reduced and system performance is improved.