Disclosed in the present disclosure are an uplink synchronization timing deviation determination method and device, for solving the problem in the prior art that a base station in an NB-IoT system has low accuracy in determining an uplink synchronization timing deviation by performing FFT and IDFT processing on a preamble sequence. The method specifically comprises: a base station receiving a preamble signal transmitted by a terminal device; determining channel estimation values of a frequency domain channel occupied for transmitting each symbol group of the preamble signal; performing, on the basis of a frequency hopping pattern used for transmitting the preamble signal, a conjugate multiplication on the channel estimation values corresponding to each symbol group to obtain a first radian value, and determining, on the basis of the first radian value, an uplink synchronization timing deviation of the terminal device.