This paper presents an estimation method of timing mismatch error in hybrid filter bank digital-to analog converter (HFB DAC). An approximated transfer function of HFB DAC with timing mismatch is derived based on the Taylor series. Then an iteration method is introduced to approach the timing error. Besides, we analyze the influence of test signal and give the requirements on test input. Using this signal, the iteration will have a fast convergence speed. Simulation experiments show the effectiveness of the proposed estimation method.