The invention discloses a pebble falling preventing compartment of a building gravel carrier vehicle. The pebble falling preventing compartment of the building gravel carrier vehicle comprises a bottom plate; the two sides of the bottom plate are each provided with a rotational driving rotation wheel; the driving rotation wheels are correspondingly connected with tires on the two sides; compartment side plates on the two sides are each provided with a U-shaped compartment top groove; each compartment top groove is internally provided with a rotational first conveying disk; the end portions of sixth rotating shafts are each connected with a sixth bevel gear; the compartment side plates on the two sides are each provided with a conveying groove correspondingly communicated with the corresponding compartment top groove; a rotational second conveying disk is arranged in each conveying groove, and the rotational second conveying disks can be correspondingly connected with the tires by means of the driving rotation wheels in the rotating process of the tires, and therefore the first conveying disks can be further driven to rotate, gravel falling into the compartment top grooves can be further conveyed, and can be further conveyed into the conveying grooves, and it is further prevented that the gravel falls onto the driving vehicle, and consequently threats on the life safety of a driver are caused.