Abstract: In this paper, aiming at the problem of large estimation error caused by instability of sampling particle weight in wideband direction-of-arrival (DOA) estimation of particle filter, an algorithm based on auxiliary particle filter is proposed. In this algorithm, the importance sampling distribution function is redefined by introducing auxiliary particle variables to large weights particle. The two-weighted calculation makes the change of the particle weight ratio more stable and the sampling point more close to the true state. In the meantime, the problem of particle degeneracy is improved and the sampling particles are guided to the high likelihood region. Simulation results show that the performance of the proposed algorithm is better than standard particle filtering method in root mean square error and detection probability.