In this paper, the features of microfluidic channel optimization are considered. The microfluidic channel is a key component of the microreactor, its shape and features of the hydrodynamic regime directly affect the successful course of chemical reactions carried out in it. The microfluidic industry regulates processes occurring in small volumes of liquids – on the order of a nano liter or less. It is applicable to various fields such as microelectronics, pharmaceuticals, specialty chemicals, etc. The Comsol Multiphysics computational modeling program was used as an optimization tool. It is based on the finite element method, which allows you to accurately model the problems of the hydrodynamic profile. In this article, the simplest form of a microchannel is considered – a 0.75 mm circular channel with a mixing cell. The mathematical modeling of the process is given, the optimality criterion adequate for the task is determined. As one of the components of this criterion, diodicity was used – a criterion that determines the ability to pass a stream in the forward direction, provided there is a reverse flow. As a result of this work, the most optimal shape of the microreactor channel satisfying the required process conditions was identified, the main hydrodynamic parameters were obtained and the dependence of the diode on the criterion used was determined.