The invention discloses a simulated projectile landslide experimental device and method. The experimental device adopts a pneumatic projectile power system including a vibration device. A simulated structural surface is arranged at the top of the vibration device; a side slope soil body is arranged at the simulated structural surface; and the inside of the side slope soil body is connected with anitrogen bottle through a ventilation pipe. A simulated rainfall device is arranged at the top of the simulated structural surface. A high-strength fiber ventilating layer, an acceleration sensor, a displacement sensor and a stress sensor are arranged between the simulated structural surface and the side slope soil body. The inside of the simulated structural surface is filled with a magnetic filler; and an electromagnet is arranged inside the side slope soil body and cooperates with a flexible iron piece disposed in a projectile soil body to generate an electromagnetic force. After simulationof the motion process of the projectile soil body under the air pressure effect and the motion process of the projectile soil body under vibration, the energy losses are analyzed and thus the real principle of causing the earthquake and projectile landslide is disclosed.