The natural frequencies of fiber reinforced composite thin plate (FRCP) under cantilever boundary condition were calculated and verified based on the way of combination of theory with experiment. Firstly

according to the structural features of FRCP

its theoretical model was established by considering the influence of fiber orientation. Then

the modal shape functions were expressed by orthogonal polynomial method and consequently natural frequencies of FRCP were theoretically calculated by Ritz method. Finally

TC500 fiber/epoxy composite thin plate was taken as a study object

and its frequency results were measured based on the established natural characteristic experiment system of FRCP. It was found by comparison that the natural frequencies calculated based on the orthogonal polynomial method had a good agreement with the experimental results

and the relative errors were within the range of 2.2%-9.7%

thus the effectiveness of above method had been verified.