The built-in stroke detection device of ceramic piston rod is a kind of built-in stroke detection device combined with ceramic piston rod. The groove is machined on the base of piston rod, and the stroke of piston rod is measured by refitting muffler with pulse signal sensor. The specific method is to machine a certain depth groove on the surface of piston rod at equal distance, and then spray ceramic material on the surface. The principle is that the base of piston rod is 45 ? steel or alloy steel, with permeability, while the ceramic material sprayed on the surface is non-metallic material without permeability. When the sensor passes through grooves of different heights, the resulting air gap will have a size, which will lead to magnetoresistance and magnetic field strength. The sensor detects the intensity of magnetic field and converts it into current intensity, and outputs impulse signal of pulse muffler effect. The sensor can detect the distance between equidistant grooves on the piston rod base, so it can be converted into the stroke of piston rod.