The invention belongs to the technical field of durability testing of concrete materials, and particularly relates to equipment and a testing method of a concrete gas permeability coefficient ring tester. It consists of a cover plate, a shell, a flowmeter, a sealing ring and a sample to be tested, wherein the cover plate is located on the top of the shell, and the sample to be tested is located in the shell. The outer wall of the cover plate is cylindrical, the interior is hollow, the cross section is circular, and the longitudinal section is U-shaped. Sealing gaskets are arranged on the top and bottom of the sample to be tested. The air inlet on one side of the shell is connected to the compressed gas tank. A connecting hole is arranged in the center of the cover plate, and the inner hollow part of the sample to be tested is connected to the flowmeter through the connecting hole. During testing, place the tested sample in the shell, open the compressed gas tank valve, test the breathability of the tested sample, keep the balance time of the tested sample at 10 minutes to 20 minutes, repeat the test 3 to 5 times for each group of tested samples, change the test pressure, repeat the test, test the gas flow through the tested sample, and calculate the average permeability coefficient of the tested sample. Take the average permeability coefficient of 3 to 5 tested samples as the test value of the tested sample. The invention has high accuracy, good test repeatability, good sealing effect, reliable test results, simple operation, small equipment and easy to carry.<o></o>