Abstract: In order to satisfy the demand for the big aperture diffraction space telescope, a primary lenses deployable structure for space membrane diffractive telescope was investigated. Firstly, after analysis of the characteristics of diffraction imaging about the big aperture membrane diffraction telescope, the main requirements for deployable structure were put forward. Then according to these design requirements for the deployable structure, a 3D solid model was designed. Finally, with the help of Adams, a simulation model was established and analyzed. The results show that the structure under the driving of the rotating drive components is in line with the design form of exercise and achieved smooth and reliable movement. This deployable structure may provide a new train of thought for the design of large aperture membrane diffraction telescope.