A demodulation method for an Orthogonal Frequency Division Multiplexing, OFDM, -Multiple Input Multiple Output, MIMO, system, comprising: a) by using a received reference signal, carrying out estimation to obtain a channel estimation value at a reference signal sub-carrier in each channel; b) by using the channel estimation value at the reference signal sub-carrier in each channel, carrying out calculation to obtain an equalization matrix at the reference signal sub-carrier; c) by using said equalization matrix to carry out an interpolation calculation, obtaining the equalization matrices for all data sub-carriers; d) by using data signals in various paths received from all of the data sub-carriers and said equalization matrices, carrying out calculation to obtain an intermediate estimation value of transmitted data; and e) by using a precoding matrix to carry out de-precoding, which means cancelling the precoding by multiplying on the left a conjugate transpose matrix of a corresponding precoding matrix, on the intermediate estimation value of the transmitted data, obtaining a final estimation value of the transmitted data, the method further comprising: in the step d), carry out calculation to obtain the intermediate estimation value of the transmitted data by employing a following formula: V ̃ 0 i k V ̃ 1 i k = G i k Y 0 i k Y 1 i k wherein, Ṽ 0 [ i, k] and Ṽ 1 [ i, k] are respectively intermediate estimation values of transmitted signals in 0 th path and 1 st path at a k th data sub-carrier within an i th OFDM symbol, G ( i,k) is an equalization matrix at the k th data sub-carrier within the i th OFDM symbol obtained in the step c), Y 0 [ i, k] and Y 1 [ i, k] are data signals in the 0 th path and 1 st path received at the k th data sub-carrier within the i th OFDM symbol respectively, k is a sequence number of sub-carrier, i is a sequence number of the OFDM symbol and k, i are both integers; in the step e), carry out calculation to obtain the final estimation value of the transmitted data by employing a following formula: X ̃ 0 i k X ̃ 1 i k = W H i k V ̃ 0 i k V ̃ 1 i k wherein, X̃ 0 [ i, k] and X̃ 1 [ i, k] are estimation values of transmitted data in the 0 th path and 1 st path at the k th data sub-carrier within the i th OFDM symbol respectively, W ( i,k) is a precoding matrix at the k th data sub-carrier within the i th OFDM symbol and W H ( i, k) is a conjugate transposed matrix of W ( i, k). a) by using a received reference signal, carrying out estimation to obtain a channel estimation value at a reference signal sub-carrier in each channel; b) by using the channel estimation value at the reference signal sub-carrier in each channel, carrying out calculation to obtain an equalization matrix at the reference signal sub-carrier; c) by using said equalization matrix to carry out an interpolation calculation, obtaining the equalization matrices for all data sub-carriers; d) by using data signals in various paths received from all of the data sub-carriers and said equalization matrices, carrying out calculation to obtain an intermediate estimation value of transmitted data; and e) by using a precoding matrix to carry out de-precoding, which means cancelling the precoding by multiplying on the left a conjugate transpose matrix of a corresponding precoding matrix, on the intermediate estimation value of the transmitted data, obtaining a final estimation value of the transmitted data, in the step d), carry out calculation to obtain the intermediate estimation value of the transmitted data by employing a following formula: V ̃ 0 i k V ̃ 1 i k = G i k Y 0 i k Y 1 i k wherein, Ṽ 0 [ i, k] and Ṽ 1 [ i, k] are respectively intermediate estimation values of transmitted signals in 0 th path and 1 st path at a k th data sub-carrier within an i th OFDM symbol, G ( i,k) is an equalization matrix at the k th data sub-carrier within the i th OFDM symbol obtained in the step c), Y 0 [ i, k] and Y 1 [ i, k] are data signals in the 0 th path and 1 st path received at the k th data sub-carrier within the i th OFDM symbol respectively, k is a sequence number of sub-carrier, i is a sequence number of the OFDM symbol and k, i are both integers; in the step e), carry out calculation to obtain the final estimation value of the transmitted data by employing a following formula: X ̃ 0 i k X ̃ 1 i k = W H i k V ̃ 0 i k V ̃ 1 i k wherein, X̃ 0 [ i, k] and X̃ 1 [ i, k] are estimation values of transmitted data in the 0 th path and 1 st path at the k th data sub-carrier within the i th OFDM symbol respectively, W ( i,k) is a precoding matrix at the k th data sub-carrier within the i th OFDM symbol and W H ( i, k) is a conjugate transposed matrix of W ( i, k).