In order to screen the optimal particle size of lotus leaf insoluble dietary fiber as a high fiber food excipient,the structure,physicochemical and sensory qualities of four particle sizes of lotus leaf insoluble dietary fibers were compared and analyzed. By scanning electron microscopy,fourier infrared spectroscopy and X-ray diffraction spectroscopy,the results showed that holes appeared on the surface of lotus leaf insoluble dietary fibers after enzymatic hydrolysis,and with the decrease of particle size,the more internal grid fibers of lotus leaf were exposed. Lotus leaf insoluble dietary fibers had the characteristic functional group structure of I-type cellulose,and with the decrease of particle size,the crystallization index of cellulose was lower.In the range of particle size studied,with the particle size of lotus leaf insoluble dietary fibers decreased,the content of total flavonoids and total polyphenols in lotus leaf insoluble dietary fibers decreased,the content of insoluble dietary fibers and in vitro adsorption capacity increased,the a* and b* of lotus leaf insoluble dietary fibers increased,and the sensory scores of the products increased. Through comprehensive comparison and analysis,it was concluded that lotus leaf insoluble dietary fiber with D₅₀ 58.35 μm had better development potential as a high fiber food excipient.