When the hard rock counter-attacking crusher works, the electric motor drives the rotor where installed hammers to rotate with high speed. When the materials get into the area which the hammers can be effective, under the impact function of the hammers at a high speed, the materials are thrown to the impact device above the rotor continuously. And then the materials are rebounded from the impact liner to the area where the hammers can be effective to be crushed again. The materials size from big to small all will be crushed in the impact chamber repeatedly. The process wont stop till the material are crushed to the required size and then will be discharged from outlet.