Our lab recently developed a new push recovery strategy for quadruped. Most existing push recovery strategies rely on Raibert heuristic regulators to adjust foot positions according to body velocities. Our proposed strategy is quite different. It is based on reachability computation, which dramatically improves the push recovery performance with theoretical support. We test our approach on the MIT Mini Cheetah. The experiments indicate that the proposed method can recover from impact twice as much as the original Mini Cheetah controller (MPC + Raibert regulator). Comparison experiments can be found in the following video.