The present invention provides a timing synchronization method comprising: performing the autocorrelation operation on a received signal with a local LAS code using a sliding window method to obtain a plurality of autocorrelation results, wherein the received signal is composed of a time domain data signal which is generated by subjecting an initial frequency domain data signal to Fourier inverse transform and a training sequence signal in a time domain, and the training sequence signal in the time domain comprises a training sequence based on the LAS code; and determining an autocorrelation peak from the plurality of autocorrelation results, using a position of the autocorrelation peak as a start position of the LAS code, and using the start position of the LAS code to determine the timing of the received signal. By designing a LAS code training sequence in the communication system, the LAS code is used in the signal receiving process to perform timing synchronization. During timing synchronization with the LAS code, the positions of training symbols are precisely found by reasonably setting the threshold, so as to improve the system timing accuracy and lay a foundation for the subsequent carrier synchronization, channel estimation and decoding process, thereby reducing the system's bit error rate.