The invention discloses an OFDM system channel estimating method, comprising: A. inserting pilot signal in OFDM symbol and making frequency-domain channel estimation on the channel at the pilot signal and obtaining frequency-domain channel estimated results; B. transforming the results from frequency domain to time domain and obtaining time-domain channel impact response estimation, and making subspace tracking on self-relative matrix of the time-domain channel estimation; C. calculating channel impact response estimation based on subspace tracking, and transforming the channel impact response estimation based on subspace tracking to frequency domain and obtaining frequency-domain channel response estimation. And it also discloses a channel estimator in OFDM system. And it can extremely improve channel estimating accuracy and reduce complexity and needs no prior statistical information, especially applicable to high-mobility and low-SNR (signal-noise ratio) environment. |