The invention relates to the field of communication, in particular to a frequency synchronizing method and device. The frequency synchronizing method comprises the following steps: extracting a burst head from a burst signal; performing frequency deviation estimation and phase deviation estimation on the burst head; performing frequency deviation compensation on a received burst signal by using the frequency deviation estimation, and performing phase deviation compensation on the received burst signal by using the phase deviation estimation; extracting unique characters from the burst signal subjected to the phase deviation compensation; performing phase fuzzy elimination on the burst signal subjected to phase compensation by using the unique characters, and synchronizing the frequency. The frequency synchronizing device comprises a first extracting module, an estimating module, a first compensating module, a second extracting module and a processing module. By adopting the frequency synchronizing method and the device, the frequency and phase deviation estimation are performed by using a non-data-aided method without using the unique characters, so that the problem of low estimation accuracy in case of a small quantity of unique characters is solved.