The invention provides a simulated fuel tank and vibration testing system for oil pump support assembly vibration experiment. The simulated fuel tank comprises a case cover, case walls and a bottom base. The case cover and the bottom base are fixedly arranged on the case walls respectively. The case wall is provided with opening holes whose sizes vary from each other. The opening holes match the sizes of the to-be-tested oil pump support assemblies. The vibration testing system comprises the simulated fuel tank and a heightened plate fixedly arranged on the bottom base. The case cover is fixedly arranged on the case walls in a detachable way. The bottom end of the oil pump support assembly is arranged on the heightened plate. According to the invention, the simulated fuel tank is provided with a plurality of opening holes, which enables the simulated fuel tank to be applied to the vibration experiments for plural oil pump support assemblies, therefore, increasing the testing efficiency. The installation requirement for the oil pump support assemblies can be fulfilled through the choice of a proper simulated fuel tank and a heightened plate so as to avoid the use of a large number of simulated fuel tanks. Only with the simple combination and installation of a heightened plate and a simulated fuel tank, the vibration testing system is provided with a simple structure and can be prepared within a short period and at a low manufacturing cost.