This paper mainly studies the positioning based on time of arrival and time difference of arrival. The quantity to be obtained is mainly time. Time of arrival measurement value can be obtained directly through symbolic timing synchronization, and its effective information can be obtained at the same time. Symbolic timing synchronization in digital video broadcast-terrestrial system can be divided into two stages: rough estimation and fine estimation. Rough estimation is based on the maximum likelihood estimation algorithm. The main purpose of rough estimation is to estimate the starting position of orthogonal frequency division multiplexing symbols, so that the starting position falls within the cyclic prefix of orthogonal frequency division multiplexing symbols. The purpose of fine estimation is to determine exactly the starting position of the orthogonal frequency division multiplexing symbol. In this paper, the symbolic timing synchronization algorithm of digital video broadcast-terrestrial system is studied and analyzed, and simulation is carried out for different channel models. Simulation results show that the synchronization algorithm achieves the best performance in additive white Gaussian noise channel and has good estimation performance in slow fading Rayleigh channel.