The invention relates to a zero-frequency-eliminating device for a space movable mechanism and belongs to the technical field of space optics. The zero-frequency-eliminating device comprises rubber wheels, rollers, a cylindrical pin, a saddle-shaped gasket, a roller seat, a first connecting bolt, an L-shaped plate and a second connecting bolt. The interior of the space movable mechanism is usually provided with a gear transmission structure, a cam transmission structure, a lead screw transmission structure, a bearing support and the like. In the structures, a certain quantity of intervals exists in the transmission links, so that when the movable mechanism vibrates at a low frequency, fine relative displacement occurs between a movable assembly and a supporting assembly. According to the zero-frequency-eliminating device, the zero-frequency intervals in the movable mechanism can be eliminated, and the zero-frequency-eliminating device has the characteristics of being simple in structure, high in assembly practicality, stable in property and high in structural adaptability; and the zero-frequency-eliminating requirements of the space high-precision movable mechanism can be met, and the property stability and imaging quality of a space optical system are effectively improved.