The invention discloses a UAT data link timing synchronization method and a device for CPFSK modulation pattern. The synchronization method of the invention comprises the following steps: firstly, calculating a one-bit difference sequence of a high-magnification oversampled baseband signal; then adding a zero value with a length of NK/2 before and after the one-bit difference sequence; extractingK groups of difference sequences according to K times at different starting positions; performing one-bit differential operation on the received baseband signal to obtain a received one-bit differential sequence; K groups of difference sequences are cross-correlated with the received one-bit difference sequence to obtain K cross-correlation values; and then K groups of difference sequences are cross-correlated with the received one-bit difference sequence to obtain K cross-correlation values. Finally, the sequence identifiers of the difference sequences with the largest cross-correlation valueare selected from the K cross-correlation values as the estimation results of symbol timing deviation. At the same time, the invention also discloses a synchronization device corresponding to the synchronization method. The invention improves the traditional high-magnification oversampling correlation algorithm through the differential operation, and proposes a new timing synchronization algorithm so as to be applicable to the UAT data link adopting the CPFSK modulation mode.