A system and method of the purification of drinking water, ethanol and alcohol beverages is based on the action of hydrodynamic cavitation processing of microbiological and chemical contaminants, micro particles and colloidal particles. The fluid flow moves at a high rate through a multi-stage cavitation device and filtration module to generate hydrodynamic cavitation features in the fluid flow. The cavitation features generate changes in the velocity, pressure, temperature, chemical composition and physical properties of the liquid. The cavitation features also prevent the deposition of contaminants upon and remove contaminants from the surface of the filter module, reduce the load on the filter elements and increase the life of the filter module.