The use of vibrational perforated sifting surfaces with holes of complex geometry provides intensive separation of loose materials by particle size and increases the technological efficiency of separating equipment. The lack of research methodologies and data on the oscillations of such perforated surfaces limits their application in practice, requires reliability studies and the derivation of appropriate patterns. The reliability analysis was conducted by studying the natural oscillation frequencies of perforated surfaces and checking for the absence of resonance phenomena. For the research, the methodology is based on numerical finite element methods in Abaqus_CAD and allows analyzing the natural oscillations of the structure when its structural parameters and boundary conditions are varied. To study the level of influence of the design of epicycloidal holes on the natural oscillations of perforated sifting surface, the identification of their values for round, epicycloidal (with a modulus of 5, 7 and 9) hole shapes was carried out. Patterns of variation in the natural oscillation frequencies of perforated surfaces are obtained depending on significant factors: surface thickness, hole spacing and epicycloid modulus. In addition, the analysis involved studying eight common modes of oscillation encountered in practice. The results were a research methodology, mathematical expressions for simplified calculation and analysis, patterns of oscillation changes of perforated sifting surfaces with holes of complex geometry. Studies enable the prediction of resonance phenomena and damage between the holes of perforated sifting surfaces, the absence of which determines their reliability.