The utility model provides a device for measuring the spacing of stirrups in a reinforced concrete structure. The device includes a rolling vehicle provided with four rolling wheels; a processor is installed in the rolling vehicle; the top of the rolling vehicle is connected with a display through a supporting rod; the display is connected with the processor through a wire; the bottom of the rolling vehicle is provided with a magnet; the magnet is provided with a pressure sensing resistor; two ends of the pressure sensing resistors are connected with an electronic voltage meter through wires; an odometer is arranged in the rolling wheel; and the odometer is connected with the processor through a wire. The device has the advantages of simple structure, accurate measurement, being convenient and reliable, and high practicability. The device can be adopted as an effective tool for detecting the spacing of stirrups for a supervision department. With the device adopted, a difficulty that the spacing of the stirrups cannot be detected in an intuitive manner after concrete pouring can be eliminated.