Based on the dynamic meshing technology, and adopting the partial joints displacement mode, the transient aerodynamic characteristics of three schemes that the heavy commercial vehicle passing the leeward side of single building, passing the windward side of single building and passing the windward side of double buildings about urban roads were studied. The displacement velocity of the mesh joint, namely the driving velocity of heavy commercial vehicle, was set at 15 m/s, and the velocity of the crosswind was 10 m/s. The results show that the effects of buildings on the transient aerodynamic characteristics are relatively obvious. During the driving, the change values of lateral force coefficient and yawing moment coefficient can be up to more than 5.0 in one second. And the corresponding change values of lateral force and yawing moment are about 12 kN and 30 kN·m, which make the peak change rates of lateral force and yawing moment reach to -12 kN·s-1and 35 kN·m·s-1.In addition, the direction of these two parameters have changed twice during the driving process.