The utility model discloses a portable concrete thickness and void tester. The hammer comprises a hammer head, the hammer head is vertically connected with an insulating and hollow protective cylinder; a sliding groove is formed in the protection cylinder in the length direction of the protection cylinder. A sliding resistor is arranged on the inner pipe wall of the protective cylinder; a conductive feeler lever is sleeved in the protective cylinder; the head end of the conductive feeler lever extends out of the other end part of the protective cylinder; a miniature camera is arranged at the head end of the conductive feeler lever, a push button is further arranged on the conductive feeler lever, the push button is exposed out of the sliding groove, a USB interface is further formed in theprotective barrel, the USB interface is electrically connected with the miniature camera while being connected with the host through a transmission line, and the sliding resistor is also connected with the host through a wire. The equipment can be used for detecting the thickness and void of tunnel initial spraying concrete, can determine the void position, can measure the void depth, can measurethe thickness of the concrete, and can image an object measured in front to determine the thickness of the concrete.