A pneumatic control rock cutting device for a rock-embedded pile soft-hard interphase layer can meet the accurate drilling requirement of the soft-hard interphase layer in the rock-embedded pile construction process, and ensures drilling quality meeting design standards. The pneumatic control rock cutting device comprises a rock cutting retaining cylinder, a conical cutting tool system, a toothed cutting tool system, a vibration sensing system, a pneumatic sensing system, a pneumatic bag system, a high-pressure water pipe, a multi-path connector, an isolation spring, a drill rod, a pneumatic controller, a vibration controller, a high-pressure water pump, a cable, power adhesives, a pneumatic flow controller, a pneumatic stabilization bolt, a rubber shock pad, an isolation fastening bolt and retaining pins. The pneumatic control rock cutting device has the advantages that according to the stress condition of soft-hard rock cutting, constant pressure of a drilled soft rock is kept, pneumatic pressure is applied to incompletely cut hard rocks, and the device solves the common problems that a rock-embedded pile easily deviates in construction in the soft-hard interphase layer and a reinforcement cage cannot descend for installation by the aid of the criterion of 'constant pressure-pressurization'.