The invention relates to a vibration isolation system with back pressing devices, and belongs to the technical field of vibration reduction of civil engineering structures. The vibration isolation system is used for controlling influences of vibration of machinery equipment on external environments or relieving influences of vibration of the external environments on the machinery equipment. The vibration isolation system comprises a counterweight bench and vibration isolators, the vibration isolators are located between a base and the counterweight bench which is supported on the vibration isolators, elastic supporting elements are arranged in the vibration isolators, and the elastic supporting elements are at least composed of metal helical springs; and the vibration isolation system further comprises the back pressing devices, each back pressing device comprises a back pressing elastic element and a connecting part, one end of each back pressing elastic element acts on the counterweight bench, the other end of each back pressing elastic element acts on the corresponding connecting part, the connecting parts is connected with the base or vibration isolator bases, and the direction of acting force of the back pressing elastic elements on the counterweight bench is opposite to that of supporting force of the elastic supporting elements on the counterweight bench. Compared with the prior art, according to the vibration isolation system with the back pressing devices, the inherent frequency is easy to control, and the vibration isolation effect is better guaranteed.