A bit field indication manner is provided. A first field is determined, where the first field includes T1 bits, at least one of the T1 bits indicates at least two elements {bi0, bi1, . . . , bik} in a set B, the at least one bit further indicates at least one element {θj0, θj1, . . . , θjh} in a set Φ, and at least one element in {bi0, bi1, . . . , bik} and at least one element in {θj0, θj1, . . . , θjh} are used to form a precoding matrix, where the set B={b0, b1, . . . , bT2−1}, an element in the set B is a vector with a length of N/4, the set Φ={θ0, θ1, . . . , θS−1}, an element in Φ is a complex number of a unit amplitude.