The application of scientifically based approaches to the intensification of natural processes of selfcleaning of soils from petroleum products is becoming increasingly important. Biocleaning is an effective, environmentally sound method of improving the environment. The purpose of the article is to establish patterns of changes in the sanitary-microbiological condition of the soil after oil pollution and to determine effective approaches to the intensification of natural processes of soil self-cleaning. In the work, the sanitary-bacteriological research of the oil-contaminated soil on sanitary-indicative microorganisms was carried out; the sanitary-microbiological condition of the studied soil samples was assessed to identify the qualitative changes in ecological and trophic groups of microorganisms; the efficiency of biostimulants application for intensification of natural processes of self-purification of oilcontaminated soils was substantiated. Methods of inoculation of medium were used for microbiological study, the degree of soil contamination was assessed by determining the total microbial count and performing the quantitative analysis of the main indicator microorganisms. It was determined that soil samples after oil inflow are heavily contaminated by sanitary and bacteriological indicators. To stimulate the development of certain groups of biotransformers, it is effective to introduce special sorbents that contain a range of substances necessary to accelerate the growth of microorganisms that destroy the oil. It was found that using the digestate of biogas plants as a biostimulator allows improving the physical and water-air properties of the soil, and acts as an effective biostimulator to increase biological activity due to the content of macronutrients.