For the fast and robust control of the delay lines for coherent pulse stacking, we combined the stochastic parallel gradient descent with momentum (SPGDM) and the soft actor-critic (SAC) into a powerful algorithm, SAC-SPGDM. The simulation shows that the algorithm can find the optimal delay-line positions to ensure the 128 pulses are coherently stacked for 7-stage pulses stacking within 25 steps.