Abstract: In order to improve the disadvantages of large grain size existed in the dietary fiber of passion fruit rind prepared by the traditional method, by using the prepared dietary fiber of passion fruit rind as the raw material, the dietary fiber of passion fruit rind was modified by the dynamic high pressure microfluidization (DHPM) to reduce the grain size of fiber. On the basis of single factor experiment, the response surface method was used to optimize the modification technology of DHPM for dietarg fiber of passion fruit shell. The results showed that the optimal conditions of modification technology of DHPM for dietary fiber of passion fruit rind were that:the ratio of solid to liquid was 1.5%, the pressure was 110 Mpa, and the treatment was 7 times. Under the optimal technological conditions, the micron-sized dietary fiber could be obtained whose secondary grain size of fiber was (32.2±1.2)μm, and the proportion of cellulose was (77.75±0.32)%. This study could provide the theoretical basis for improving the physicochemical properties of dietary fiber of passion fruit rind and promote the high-value utilization of passion fruit rind.