The invention discloses a concrete spreading and paving machinery used for building construction. The concrete spreading and paving machinery used for building construction comprises a fixing base, a piston block is connected with the inner side of a through pipe in a clamping mode, a jacking rod is connected to the top of the piston block, a material guiding plate is connected to the top of a clamping base, and mounting holes are formed in the inner side of a mounting rod at equal intervals; a mounting pipe is connected to the left side of the top of the fixing base, a movable rod is connected to the inner side of the mounting pipe in an inserting mode, a movable spring is connected to the top of the movable rod, and through holes are formed in the inner side of the movable rod at equal intervals; and the right side of a threaded rod penetrates through one of the through holes and is connected with a nut in a threaded mode, a second gear track is engaged with the left side of a transmission gear, and a brush plate is connected to the side, far away from a cleaning rod, of a compression spring. The concrete spreading and paving machinery used for building construction has the advantages that uniform discharging can be achieved during discharging of concrete and the concrete paving thickness is convenient to control, and the problem that practicability of the concrete paving machinery is reduced due to the facts that discharging of concrete is nonuniform and the concrete paving thickness is difficult to control is solved.