The invention discloses a method for channel estimation in a broadband wireless mobile communication system and a channel estimator. The method comprises the following steps: 1) pilot channel estimation is carried out by adopting a given algorithm to each pilot symbol in a plurality of pilot symbols transmitted by the channels, in pilot subcarriers within the usable subcarrier range, boundary value reprocessing is carried out to virtual pilot falling into the high frequency virtual subcarrier range so as to obtain the channel frequency response estimation of equal-interval pilot subcarrier position in a plurality of pilot symbols; 2) reverse Fourier transform is carried out to the channel frequency response estimation of the equal-interval pilot subcarrier position in a plurality of pilotsymbols, so as to obtain time-domain channel impulse response estimation of a plurality of pilot symbols, and the time-domain channel impulse response estimation of the data symbol is obtained by adopting the given algorithm; and 3) after zero value insertion processing is carried out to a plurality of pilot symbols and the obtained time-domain channel impulse response estimation of the data symbol, the channel estimation result can be obtained by adopting the Fourier transform. The invention improves the accuracy and the robustness of the channel estimation.