The invention discloses a test method for testing the service life of a hydro-pneumatic spring. The test method is conducted by means of a hydro-pneumatic spring test stand. The test method comprises the steps of 1, testing the static characteristics of a hydro-pneumatic spring; 2, testing the dynamic characteristics of the hydro-pneumatic spring; 3, testing the service life of the hydro-pneumatic spring; 4, returning to the step 1 when the oil liquid cleanliness of the hydro-pneumatic spring is in the normal state; 5, circularly executing the above process from the step 1 to the step 4. When the hydro-pneumatic spring conducts 240 million times of shock excitation after completing 12 cycles of the step 3, the test is terminated. When the leakage state, the sealing state and the oil liquid cleanliness state are normal, the hydro-pneumatic spring passes the test assessment on the service life of a corresponding mileage, wherein the 240 million times of shock excitation during 12 cycles corresponds to the vehicle travel of 6 ten thousand kilometers. The test method has the advantages of convenient implementation, scientific and reasonable properties, high reliability, and high practicability.