The invention discloses an estimation method for low-complexity channel in a time division duplex (TDD) multi-base station cooperative system, belonging to the field of wireless communication technology. The estimation method comprises the steps of: acquiring a frequency domain signal and a primary time domain signal vector, setting a primary iteration counting variable m to be equal to 0, acquiring a primary time domain channel vector, acquiring a time domain signal vector vm+1 after being subjected to m+1 iterations, acquiring the time domain channel vector after being subjected to m+1 iterations, updating a circulating counting variable m, and if m is greater than P, continuously acquiring a time domain signal vector, otherwise, obtaining frequency domain channels of K users. According to a channel estimation algorithm provided by the invention, matrix inversion in a minimum mean square error algorithm is converted to matrix power series by utilizing a series expansion manner, multiplication of matrix and vector can be realized by means of fast fourier transform and inverse fast fourier transform, the estimation method has the advantages of low complexity and excellent property, and can be realized without small-scale statistics information of the channel.