The invention discloses a rock crushing device and method. The rock crushing device comprises a crushing device and a sealing device; the crushing device is a sleeve type liquid bag crushing device ora mixed type liquid bag crushing device; the sleeve type liquid bag crushing device comprises a first circular liquid bag, the circular space between the inner wall and the outer wall of the first circular liquid bag is filled with a liquid, and the cylindrical space defined in the inner wall of the first circular liquid bag is filled with an emulsion explosive; the mixed type liquid bag crushingdevice comprises a circular mixed type liquid bag, the circular mixed type liquid bag is formed by butt-jointing of two semi-circular liquid bags, the two semi-circular liquid bags include a liquid filled bag and a gas filled bag, the semi-circular space between the inner wall and the outer wall of the liquid filled bag is filled with a liquid, the semi-circular space between the inner wall and the outer wall of the gas filled bag is filled with a gas, and the cylindrical spaces defined in the inner walls of the liquid filled bag and the gas filled bag are filled with emulsion explosives; thesealing device comprises a cylindrical sealing bag and a stemming material; the cylindrical sealing bag is a cylindrical liquid bag; and the stemming material is located on the outer side of the cylindrical sealing bag.