The invention relates to the technical field of hydraulic material nondestructive detection, in particular to a method for evaluating structural performance of an epoxy mortar thin layer through R-wave frequency dispersion characteristic. The method comprises the steps that an excitation hammer with the suitable size, the spacing between two receiving sensors and the spacing between the excitationhammer and the sensors are determined; elastic waves are generated at a designed excitation point in a hammering mode, and acceleration sensors are arranged on designed measuring points to correspondingly receive R-wave signals propagated through the epoxy mortar thin layer at different times; by analyzing and processing the R-wave time-domain signals received by the two or more sensors, a phasedifference frequency spectrum and the R-wave velocity of the signals are gained, and a phase frequency spectrum and a frequency dispersion curve are established; a formula for judging the performanceof the epoxy mortar thin layer through R-wave parameters is analyzed and deduced, and the feasibility of using the phase frequency spectrum and the frequency dispersion curve for judging is defined; and by analyzing and processing the R-wave signals at the different measuring points, the performance of the epoxy mortar thin layer is judged. The effective means is provided for efficiently and rapidly obtaining performance parameters of the epoxy mortar thin layer.