To explore the effect on the physicochemical and structural properties of thebamboo shoots dietary fiber （BSDF）, square bamboo shoots dietary fiber was used toas raw material to obtain BSDF with different pressure （0, 50, 100, 150, 200 MPa） by dynamic high pressure micro-fluidization （DHPM） treatment. Results showed that as the treatment pressure increases, the particle size of BSDF firstly increased and then decreased. When the treatment pressure was up to 150 MPa, the particle size reached the minimum （370±11） nm. The water holding capacity, oil holding capacity and swelling capacity reached the maximum, which were increased by 47.74%, 50.54% and 61.27% respectively,compared with the untreated group.Infrared spectroscopy analysis showed that the main functional groups of BSDF did not change after DHPM treatment, but the hemicellulose and lignin inside the BSDF degraded and some hydrogen bonds broken. The X-ray diffraction and thermal gravity analysis showed the crystal structure of BSDFdid not change, however, the crystal order decreased, which lead to a decrease in its thermal stability. Microstructure analysis showed that DHPM treatment reduced the size of BSDF particles, roughened the surface, and loosened the structure. And when the processing pressure increased to 200 MPa, the particles agglomerated. Above results shows that DHPM can effectively improve the physicochemical properties of BSDF and has certain application value in modification of dietary fiber.