The electric hammer has high efficiency, large hole diameter and long drilling depth. The principle of electric hammer is that while the transmission mechanism drives the drill to rotate, there is also a reciprocating hammering movement perpendicular to the rotary head. The electric hammer is a kind of hammer that drives the piston to and fro compress air in a cylinder by the transmission mechanism. The periodic change of air pressure in the cylinder drives the hammer in the cylinder to and fro hit the top of the brick, as if we hit the brick with a hammer, so it is called the electric hammer.