For an unmanned helicopter optoelectronic system, the external passive vibration isolation platform was designed and verified based on the Hexapod configuration. The dynamic model of the Hexapod vibration isolation platform was established, the parametric modeling of the platform was completed, and the theoretical analysis and simulation comparison of the digital prototype were carried out based on Adams and Simulink co-simulation to verify the accuracy of the modeling. The sweep frequency test and the line/angle coupling response test of the developed prototype were conducted. The results show that the natural frequency of the three-direction linear excitation of the vibration isolation platform is less than 8 Hz, which can realize the vibration attenuation of the main vibration frequency of the helicopter platform, and the RMS value of coupling angle swing response is less than 200 μrad. Finally, the field hanging flight test was completed, which verified that the engineering prototype of the vibration isolation platform met the operational requirements.