A method, a codebook, and a Base Station (BS) for precoding are provided. The precoding method includes: obtaining a total uplink power of a User Equipment (UE); if the total uplink power is greater than ¾ of a rated total transmit power of antennas, selecting a codeword from a first codebook with imbalanced power between layers; otherwise, selecting a codeword from the first codebook and a second codebook with balanced power between layers, so as for precoding data to be transmitted according to the selected codeword.