In order to realize the lightening of aerial camera, a wide-area array sweep camera installed on the front web mounting board of an unmanned aerial vehicle (UAV) is designed and its main frame is optimized. Firstly, the overall design of the swing mechanism is carried out according to the structural limitation of the UAV mounting plate. Then, the size of the main frame of the swing mechanism is optimized by using OptiStruct software. After, the modal analysis, static analysis and random vibration analysis of the main frame and the whole swing mechanism of the swing mechanism under different working conditions are carried out respectively by using finite element analysis method. Finally, the sinusoidal sweep test in Y direction is carried out for the sweep mechanism. After optimization, the mass of the main frame is 1.2 kg, the natural frequency of the swing mechanism avoids the excitation frequency of the vibration source, the maximum stress and deformation of the swing mechanism are 62.35 MPa and 1.03 mm, respectively, and the frequency value at the resonance frequency of the shock absorber is 27 Hz. Wide area array swing camera basically meets the requirements of lightening and miniaturization. The natural frequency, stress and deformation of the swing mechanism meet the design requirements.