A dwell time optimization method on particle swarm optimization algorithm is proposed for the high-precision magnetorheological machining of optical components based on pulse iteration principle. This method introduced the particle swarm optimization algorithm to optimize the residual error of the overall surface on the basis of the pulse iteration method. Through the determination of the overall dwell time, the optimal selection of each dwell time point was realized and the high-precision surface machining was achieved. The root mean square (RMS) and peak valley (PV) values of Φ156 mm optical surface simulation converged from the initial 169.164 and 1 161.69 nm to 23.492 5 and 807.215 6 nm. The simulation results show that the proposed algorithm not only ensures the accuracy of surface convergence, but also obtains stable and reliable dwell time distribution. The proposed algorithm is better than the common pulse iteration method, effectively reducing the mid-spatial error. This algorithm provides a solution for the dwell time calculation in the process of magnetorheological finishing optical components.