The invention discloses a portable core gas logging permeability measuring device which comprises a core, a pressure sensor and a cylinder body, and further comprises a hand-operated hydraulic pump, a rubber sleeve, a piston, a piston drive device, a computing chip and a hydraulic display, and an emptying valve, wherein the core is placed in the cylinder body, the rubber sleeve is arranged between the core and the cylinder body, the hydraulic pump is arranged at the outer side of the cylinder body and connected with the rubber sleeve, the piston and the piston drive device are arranged in the cylinder body, an inner cavity is formed between one end face of the core and the piston, and the pressure sensor, the computing chip and the liquid crystal display as well as the emptying valve are arranged at the outer side of the cylinder body and connected with the inner cavity. The portable core gas logging permeability measuring device disclosed by the invention is small in volume, simple in structure, convenient to carry, and suitable for measuring permeability in field or well-drilling site.