Said invention refers to concrete gaseous permeability coefficient uniaxial compressive stress tester and testing method belonging to concrete material viability detection technique field. It contains dying, dying sample room, supporting frame, lifting jack, pressurizing plate, compressed gas tank, and pressure gauge etc, wherein dying consisting of dying cover board and dying bottom case, dying sample room located in dying bottom case, dying cover board and dying bottom case respectively set with outgoing gas chamber, intake chamber in turn connected with inlet valve, compressed gas, and pressure gauge, lifting jack and pressurizing respectively located at two ends of test sample, one side of dying bottom case set leakage check groove. In testing, tested sample is located in dying sample room, pressing in wedge, screwing dying, checking leak tightness, starting up lifting jack, applying compressive stress in test sample, opening compressed gas tank valve, keeping tested sample equilibration time being 10-20 minute, each tested sample repeating testing gas permeation time by more than 3-5 times, changing test pressure and repeat testing, to obtain tested sample permeability coefficient average value, taking 3-5 tested sample permeability coefficient average value as test value of said group tested sample. Said invention has easy and simple to handle, reliable test result, assembly type unit, and convenient for carrying.