This paper studies an algorithm on frame and symbol timing synchronization in burst OFDM communication based on IEEE802.11a, and analyzes the effect of symbol timing synchronization error. Itpsilas not perfect in many algorithms on timing synchronization at present, such as high complexity, floated threshold along with the signal energy. Therefore, it's necessary to propose an algorithm on symbol timing synchronization using the specialty of short training sequence in this paper. The analysis and the simulation results show that the algorithm proposed in this paper can improve the bit-error-rate performance of the system effectively. Moreover, it also has an adaptive threshold and low implementation complexity. Therefore, the proposed algorithm is suitable for fast symbol timing synchronization in burst OFDM system.