A series of sand true triaxial shear simulation tests were performed using the discrete element method, so as to investigate the effect of inter-particle rotational impedance on the mechanical properties is discussed from macro-and microscopic perspectives. Analyze the mechanical properties of sand under different rolling resistance coefficients, and explain the influence mechanism of rotation resistance from a micro-level perspective. The results show that as the rolling resistance coefficient increases, the peak deviator stress and its corresponding peak internal friction angle increase correspondingly, and the softening phenomenon gradually intensifies. At the micro-level, the influence mechanism of rotational impedance is analyzed from the perspective of effective coordination number, probability density, the normal contact force between particles, and anisotropy. The study further found that the rotational resistance inhibited the relative rotation between sand particles, resulting in a decrease in the average coordination number between sand particles; the probability density of strong contact force between sand particles and the size of the contact force both increased with the increase of the rolling resistance coefficient; intuitively qualitatively analyze the influence of different rotational impedances on the normal contact force and stress-induced anisotropy through the three-dimensional histogram, and combine the second invariant to characterize the anisotropy of the fabric tensor and the normal contact force tensor, it is found that the anisotropy coefficient increases with the increase of the rolling resistance coefficient.