The invention discloses a portable photo-ionization detector which comprises a detection head, an abnormal indicating lamp, a work indicating lamp, a fixed panel, a display screen, a switch, a detector body, an anti-slip bulge and a protecting shell; the protecting shell is fixed outside the detector body; a selection key is arranged on the front surface of the detector body in an embedding manner. The portable photo-ionization detector disclosed by the invention has the beneficial effects that as the protecting shell is arranged, a function key and a digital key can be protected when the detector body stops work; as a limiting column and a jack are formed, a hanging ring can be conveniently fixed, and further the detector body can be conveniently placed; as an anti-slip supporting pad is arranged, the problem that the detection head is in contact with a tabletop to result in damage can be further solved; as a rotating shaft and a shaft seat are arranged, the fixed panel can be conveniently rotated, and further the fixed panel can be protected; meanwhile, staff can conveniently observe and record detection data; the portable photo-ionization detector is convenient to mount and carry and simultaneously easy to place.