Abstract Objective To analyze the hip parameters and the dynamic changes of the space between femur and ischium in patients with ischiofemoral impingement syndrome(IFI).Methods From January 2018 to December 2019, 17 patients (29 hips) with IFI were selected as the observation group and 20 patients (40 hips) with normal hip joint as the control group. The CT images of the two groups were imported into Mimics17.0 and Geomagic studio 10.0 in DICOM format, to reconstruct the three-dimensional models , and than the model component was imported into SOLIDWORKto simulate the abduction, adduction, extension and flexion movements with the center of the femoral head as the axis. The ischiofemoral space(IFS), femoral offset, femoral neck angle, femoral neck long axis,lesser trochanter height, anteversion angle, ischial distance and ischial angle were measured.Results The femoral offset, femoral neck long axis and anteversion angle of the observation group were significantly smaller than those of the control group (P < 0.05). The femoral neck angle,less trochanter height and ischial distance were significantly higher than those in the control group (P < 0.05). The IFS in the observation group was significantly smaller than that in the control group (P < 0.001). ④Abduction and internal rotation could significantly increase the IFS,But adduction and external rotation could reduce the IFS. The effect of hip joint movement on the IFS in the observation group was smaller than that in the control group.Conclusion The increase of anteversion angle of femur, the lesser trochanter height and the decrease of the femoral neck long axis were the main factors that lead to the decrease of IFS. Abduction and internal rotation of the hip would be beneficial to increase the IFS and relieve the pressure of quadratus femoris.