Since 2017, laboratory staff have been developing computer models for simulating the process of solid-phase microextraction of organic compounds from air, water, and soil using COMSOL Multiphysics. The developed models significantly reduce the time and other costs associated with optimizing the parameters of solid-phase microextraction, as well as test the method under complex conditions and identify potential issues. To use the model, only the distribution constants of analytes between all phases involved in the process and their diffusion coefficients are required. Currently, we optimize at least half of the parameters of the developed methods using the available models.