Rubber diaphragm failure is the main failure mode of the diaphragm accumulator. Based on the working principle of diaphragm chamber of gas accumulator, the axisymmetric finite element model is established, in which the rubber diaphragm material by Ogden constitutive model, and the gas in the accumulator using the fluid element in ABAQUS to simulate. Calculating the stress distribution under the maximum gas pressure through the implicit nonlinear finite element analysis, so as to guide reasonable diaphragm design.