An invention relates to mechanical engineering, in particular to a method of manufacturing plain bearing friction surfaces. A method of manufacturing plain bearing friction surfaces includes treatment of the working layer, which includes the transformation of the upper layer of the working surface by electro-plasma method in an alkaline electrolyte at a pulse voltage between anode and cathode up to 1200 V to form a layer of aluminium oxide (Al2O3). According to the invention, the upper layer of the working surface, which is made of aluminium-tin alloy, is treated. The plain bearing is used as the anode and processed at a pulse voltage between the anode and cathode up to 600-1200 V at a current density from 1.0.104 to 1.2.104 A/m2. The upper layer of the working surface is converted to a depth of 20 to 70 μm, forming a running-in layer of aluminium (Al2O3). The invention improves the manufacturing of the plain bearing friction surface, which significantly improves the performance of the plain bearing during operation.