Modulation transfer function (MTF) resulting from random vibration was analyzed.The effect angular displacement was regarded as major factor to affect the image of aerial camera.Allowable MTF degradation was represented,and allowable MTF degradation was converted into stable system design parameters.The parameters can guide perfect design for stabilization system.Based on the spatial mechanism and translational principle of parallelogram,an irrotational displacement isolator was developed,which can meet the requirements of irrotational displacement and damp.An instance was given,and 34 dB reduction was achieved at frequency of 100HZ.With the help of MSC.ADAMS simulation software,curve proves correct for isolator was simulated,and the irrotational displacement mechanism was tested by optical method with coupled angle being less than 8″,which can satisfy the demand of aerial imaging.