The invention provides a test device of an oil and gas suspension system. The test device comprises a foundation, the oil and gas suspension system, an excitation hydraulic cylinder, a pressure sensor connected with the excitation hydraulic cylinder and a hydraulic servo control system used for controlling motion of the excitation hydraulic cylinder, wherein the oil and gas suspension system comprises one or more oil and gas suspension cylinder sets mounted on the foundation and an energy storage device connected with the oil and gas suspension cylinder set through a pipeline, the two oil and gas suspension cylinders of the oil and gas suspension cylinder set are connected in an opposite mode through a connection head, the excitation hydraulic cylinder is mounted on the foundation, and a cylinder lever of the excitation hydraulic cylinder is parallelly connected with the middle portion of the connection head. The test device is advantaged in that test analysis on inclination performance of the one or more oil and gas suspension cylinder sets is realized through the one excitation hydraulic cylinder, and test cost is substantially reduced.