In this paper, the particle penetration coefficient of a multibended building crack was numerically investigated in detail. A steady laminar flow field was obtained by solving continuity and Navier–Stokes equations. The Eulerian method considering gravitational sedimentation and Brownian diffusion was employed to describe particle behavior and was validated using the experimental data. This study evaluated the particle penetration coefficient of straight-through, L-shaped, double-bend, and four-bend cracks by considering the following impact factors: the ratio of the vertical–horizontal wall area, crack height, and inclined wall angle. The results show that the ratio of the vertical–horizontal wall area is a key parameter for evaluating the particle deposition rate. When particles travel through the L-shaped crack, the penetration coefficient of fine particles is the same for cracks with different ratio of the vertical-horizontal wall area, and the penetration coefficient of large particles increases with increasing the ratio of the vertical-horizontal wall area. The particle diameter band with a penetration coefficient higher than 80% extends with increasing crack height. If L-shaped cracks have constant ratio of the vertical-horizontal wall area, then the particle has equal penetration coefficients when traveling through L-shaped cracks inclined at different angles. Particles traveling through multibended cracks with equal length, height, and ratio of the vertical-horizontal wall area exhibit the same trend for penetration coefficients.