A channel estimation method in a multi-antenna system, characterized by comprising: for each uplink user received by a base station array antenna, obtaining an original channel estimation value for each array element of the array antenna; generating a channel estimation matrix using the obtained original channel estimation values, wherein the channel estimation values associated with each array element form a respective row vector of the channel estimation matrix, and the channel estimation values of respective array elements corresponding to a location of each channel estimation tap form a respective column vector of the channel estimation matrix; dividing the channel estimation matrix into a channel estimation amplitude matrix and a channel estimation phase matrix; grouping, in the channel estimation amplitude matrix, the channel estimation values associated with the respective array elements at one corresponding tap location together for signal transformation processing and performing the signal transformation processing on each group, wherein the signal transformation processing is one selected from the group consisting of: Discrete Fourier Transformation, Discrete Cosine Transformation and Discrete Wavelet Transformation; applying a transform-domain noise reduction to a high-frequency portion of transform-domain data obtained by the signal transformation processing, wherein applying the transform domain noise reduction to the high-frequency portion of the transform domain data obtained by the signal transformation processing further includes setting the high-frequency portion of the transform domain data to zero; obtaining a noise-reduced channel estimation amplitude matrix by applying an inverse transform to the noise-reduced transform domain data; and combining the noise-reduced channel estimation amplitude matrix with the channel estimation phase matrix into a restored channel estimation matrix, wherein the amplitude of each channel estimation value of the restored channel estimation matrix has undertaken a multi-antenna transform domain noise reduction process. for each uplink user received by a base station array antenna, obtaining an original channel estimation value for each array element of the array antenna; generating a channel estimation matrix using the obtained original channel estimation values, wherein the channel estimation values associated with each array element form a respective row vector of the channel estimation matrix, and the channel estimation values of respective array elements corresponding to a location of each channel estimation tap form a respective column vector of the channel estimation matrix; dividing the channel estimation matrix into a channel estimation amplitude matrix and a channel estimation phase matrix; grouping, in the channel estimation amplitude matrix, the channel estimation values associated with the respective array elements at one corresponding tap location together for signal transformation processing and performing the signal transformation processing on each group, wherein the signal transformation processing is one selected from the group consisting of: Discrete Fourier Transformation, Discrete Cosine Transformation and Discrete Wavelet Transformation; applying a transform-domain noise reduction to a high-frequency portion of transform-domain data obtained by the signal transformation processing, wherein applying the transform domain noise reduction to the high-frequency portion of the transform domain data obtained by the signal transformation processing further includes setting the high-frequency portion of the transform domain data to zero; obtaining a noise-reduced channel estimation amplitude matrix by applying an inverse transform to the noise-reduced transform domain data; and combining the noise-reduced channel estimation amplitude matrix with the channel estimation phase matrix into a restored channel estimation matrix, wherein the amplitude of each channel estimation value of the restored channel estimation matrix has undertaken a multi-antenna transform domain noise reduction process.