This study investigated the changes of structure and functional properties of insoluble dietary fiber (IDF) from lotus root residue before and after alkaline hydrogen peroxide (AHP) treatment. Results showed that D-glucose content of lotus root residue IDF increased significantly by 9.52% (P<0.05)， while the contents of other monosaccharides decreased significantly (P<0.05) by AHP treatment. Scanning electron microscopy analysis showed that IDF had fluffy structure and wrinkled surface after AHP treatment. The results of X-ray diffraction indicated the crystal structure of IDF did not change after AHP treatment， but the diffraction intensity increased from 13.09% to 16.13% (P<0.05). Infrared spectroscopy indicated the breakage of some chemical bonds of IDF after AHP treatment， and the characteristic adsorption peaks weakened or disappeared. Thermogravimetric analysis showed that after AHP treatment， the peak pyrolysis temperature of IDF decreased， but the mass residue rate increased from 10.43% to 15.94% (P<0.05). Moreover， the water holding capacity， oil holding capacity， cholesterol adsorption capacity， Cu2+ adsorption capacity and cation exchange power of IDF were effectively enhanced (P<0.05) after AHP treatment， sodium nitrite adsorption capacity of did not change significantly (P>0.05)， while the expansion capacity was greatly reduced (P<0.05). These results suggested that AHP treatment can change the structure of lotus root residue IDF and improve its functional properties.