Embodiments of this application disclose a channel estimation method and apparatus, and relate to the field of communications technologies. The method may include: generating and sending indication information, where the indication information is used to indicate L space-frequency basis vectors for constructing an M×N-dimensional space-frequency vector; the space-frequency vector includes M N-dimensional precoding vectors, each precoding vector is used in one of M frequency bands, and the space-frequency vector is generated by performing a weighted combination on L space-frequency component vectors; each of the L space-frequency component vectors is a vector including M×N elements that are in one of the L space-frequency basis vectors, and each of the L space-frequency basis vectors is an Nf×N-dimensional vector; the space-frequency basis vector is a three-dimensional oversampled (DFT) vector; and L≥2, Nf≥M≥1, N≥2, and L, M, N, and Nf are all integers.