Products of fast pyrolysis of organic materials (bio-oil) have such advantages as ease of storage and transportation, production from renewable raw materials, but have not yet found wide application as motor and boiler fuels. The article describes the results of research aimed at obtaining such fuel containing petroleum fuel oil and bio-oil as the main components. Direct mixing of these components is a difficult task due to their chemical incompatibility. Its solution required the development of technology and devices, which was the purpose of the presented research results. The research methodology was based on mathematical modeling of the processes of mixing fuel components, analysis of its results, their transfer to natural samples and their experimental study. As a result, a technology and design of mixers were developed that made it possible to obtain a stable mixed fuel containing fuel oil and bio-oil in the following proportions of the mass ratio up to 50:50. The obtained results confirmed the correctness of the chosen approach, which made it possible to develop new technology and equipment to achieve the stated research goal.