The invention discloses a signal sample rate conversion method and device. According to the method and the device, after a first time domain signal sequence of N sample points is collected, the first time domain signal sequence is converted into a first transform domain signal sequence; the first transform domain signal sequence is processed to obtain a second transform domain signal sequence according to a ratio of a second sample rate and a first sample rate; the number of the sample points contained in the second transform domain signal sequence is the product of the N and the ratio; the second transform domain signal sequence is converted into a second time domain signal sequence; and the sample rate of the second time domain signal sequence is the second sample rate, so the conversion from the first sample rate to the second sample rate is realized. Compared with a method of carrying out signal sample rate conversion in a time domain, the method has the advantages that the signal sample rate conversion is carried out based on a transform domain, the processing cost is reduced, the realization complexity is reduced and the processing precision is improved.