To investigate the mechanical properties and particle breakage effect of construction solid waste, a series of static and dynamic direct shear tests were carried out using a dynamic interface shear tester. Different coarse particle contents (40%, 50%, and 60%), amplitudes (45 kPa, 60 kPa, and 75 kPa), and frequencies (0.5 Hz, 1 Hz, and 2 Hz) were used as variables, and the variation rules of shear stress?shear displacement curves, shear strength parameters, and particle breakage under three normal stresses (50 kPa, 100 kPa, and 150 kPa) were analyzed. The results indicate that under the same initial normal stress, with the increase of coarse particle content, the shear strength, internal friction angle, and relative breakage rate of construction solid waste increase, while the cohesion decreases. With the increase of amplitude and frequency, the shear strength, cohesion, internal friction angle, and relative breakage rate of construction solid waste all decrease. The shear stress?shear displacement curves all exhibit a strain-softening type; during the shear process, fluctuation phenomena occur in the shear stress?shear displacement curves. The particle size distribution curves after shearing show an overall upward shift trend, and with the increase of normal stress, the upward shift amplitude of the curves increases.