A dynamic compensation device for radio frequency ripple signals of an optical storage system is disclosed. The device is composed of a radio frequency ripple signal process circuit, a radio frequency signal process circuit, a radio frequency signal peak detector, a first analog to digital converter, a second analog to digital converter, a defect detector, and a fingerprint detector. The drop-out of the central level of the radio frequency ripple signal is eliminated, and the track cross waveform is prevented from being damaged.