Abstract: There are some vibrations in farming moving vehicle. This demands a high reliability for the precision electronic equipment in farming moving vehicle. The aim of this article is to provide a systematic method for designing a multi-medium coupling double isolator for precision electronic equipment in farming moving vehicles. A mathematical model of a multi-medium coupling double isolator was built for the demand of attenuating vibration based on actual applying. The coupling of quadratic damping, viscosity damping, coupling damping and nonlinear spring were introduced in the model. The approximate theoretical calculating formulae were deduced by combining linear transform, LAPLACE transform method. The working characteristics of the model and the parameters selection of the isolator were discussed based on determinated excitation or random excitation situation. Some calculating formulae about mean square value of acceleration, velocity and displacement were deduced. An example was introduced to illustrate the validity of the model. So the study establishes theoretical basis for progress research of the multi-medium coupling double isolator.