The invention provides a signal-to-noise-ratio estimation method which is used for estimating the signal to noise ratio of a receiving signal according to pilot frequencies inserted into the receiving signal. The signal-to-noise-ratio estimation method includes the following steps: S1, a pilot frequency numerical value Xm, k, a channel estimation value Hm, k and Gaussian white noise Nm, k of the positions where the pilot frequencies are located are obtained from the receiving signal, wherein the m and the k show that the corresponding pilot frequencies are located at the mth data symbol and the kth subcarrier; S2, pilot frequency position information Ym, k of the positions where the corresponding pilot frequencies are located is obtained according to the pilot frequency numerical value Xm, k, the channel estimation value Hm, k and the Gaussian white noise Nm, k; S3, a signal-to-noise-ratio estimation value of the receiving signal is obtained according to the pilot frequency numerical value Xm, k, the channel estimation value Hm, k and the pilot frequency position information Ym, k. By means of the signal-to-noise-ratio estimation method, under the condition that the number of the pilot frequencies inserted into data symbols is limited and a large amount of statistics cannot be carried out, contiguous items between the noise and the signal can be eliminated, the accuracy and the stability of the algorithm estimation value can be optimized, and the computing complexity can be simplified.