Based on the problem of earth pressure concentration in earth pressure cells, a water bladder earth pressure gauge was invented. The thickness of pressure sensing water bladder can be controlled within 5~10 mm. The pressure sensing water bladder is connected with the electronic pressure gauge through the transparent PU air pressure hose. The height position of the electronic pressure gauge needs to be fixed when the water bladder earth pressure gauge is used. A comparison test was conducted between the water bladder earth pressure gauge and the vibrating string earth pressure cell buried in soils with different compression modulus. The analysis of the results shows that, although the problem of high measured earth pressure is unavoidable, the stress concentration problem is significantly improved when the earth pressure in the stratum is tested with the water bladder earth pressure gauge compared with the earth pressure cell as the pressure sensing water bladder being thinner than the earth pressure cell. From the test results, it can be seen that the amplitude of soil pressure caused by the thickness of the test element is non-linear, which is related to the adjustment of soil particle deformation around the test element. The water bladder earth pressure gauge is used in the model test of shield tunnel response. The test results show that the water bladder earth pressure gauge is obviously different from the earth pressure cell. From the analysis of the changing trend of the test results, the test results of the water bladder earth pressure gauge are reliable and it is necessary to use a water bladder earth pressure gauge directly attached to the outer wall of the model shield tunnel to test its surrounding soil pressure. The test principle of the water bladder earth pressure gauge is simple with low cost, and the precision is high. Because of its flexible construction, the pressure sensing water bladder can be used to test the earth pressure of non-plane structure surface according to the test demand.