The principle of stone crushing: 1, extracorporeal shock wave lithotripsy, it is the use of extracorporeal shock wave lithotripter to send out electronically radiated electromagnetic waves, through the water capsule in contact with the human body, the electromagnetic waves gathered in focus, the focus on the human body above the stone, that can produce the principle of air blasting, so that the stone inside the tiny volume of air suddenly increased, to produce a certain blasting force will be blasting the stone to break. Similar to the use of solar energy to boil water, the use of curved solar panels to reflect the sunlight, the focus of the sunlight gathered in a point, the temperature of this point will increase, will turn cold water into hot water, the principle is similar to the principle of extracorporeal shock wave lithotripsy. 2, laser lithotripsy is the use of ureteroscopy or kidney and after reaching the stone site, the laser directly contact with the surface of the stone, the laser can make the stone around the water vaporization, and produce a lot of tiny bubbles. 3.Pneumatic ballistic lithotripsy uses mechanical force to break the stone, so the force of breaking the stone is greater, but the effect of crushing the stone is poor.