The invention provides an intershaft bearing vibration experiment device. The intershaft bearing vibration experiment device comprises an experiment table base, a high-pressure rotor system, a low-pressure rotor system, a test system, a load simulation device and a temperature environment simulation device, wherein the high-pressure rotor system and the lower-pressure rotor system are used for allowing an inner sleeve ring and an outer sleeve ring of an intershaft bearing to rotate at different speeds, the test system is used for testing, transmitting and acquiring a vibration signal of the intershaft bearing, the load simulation device is used for simulating a centrifugal load and a radial load which are borne by the intershaft bearing, and the temperature environment simulation device is used for simulating a high-temperature environment of the intershaft bearing. In the intershaft bearing vibration experiment device provided by the invention, the simulation of the temperature environment and the load characteristic of the intershaft bearing is achieved, and meanwhile, the interference of other parts on the vibration signal of the intershaft bearing is prevented; and the proposed intershaft bearing test method is used for directly testing surface vibration of an inner circle and an outer circle of a bearing body, and the vibration characteristic of the intershaft bearing body can be effectively analyzed.