The present disclosure provides a vacuum cleaner floor brush with a height-adjustable suction inlet. The vacuum cleaner floor brush includes a floor brush main body, a rolling brush, and a rolling brush cover with an arc-shaped cross section; the rolling brush is fixedly mounted on a preset rolling brush chamber on the floor brush main body; the floor brush main body is provided with a suction inlet adjustment plate; an inner wall of the suction inlet adjustment plate is a cambered surface; a lengthwise direction of the suction inlet adjustment plate is parallel to an axial direction of the rolling brush; two opposite ends in a width direction of the suction inlet adjustment plate respectively extend towards the rolling brush cover and a bottom suction inlet of the floor brush main body; and the suction inlet adjustment plate can flip along a circumferential direction of the rolling brush. In the present disclosure, more than two kinds of different rolling brushes can be mounted on the same floor brush for use. When different rolling brushes are used on different floors, the suction inlet adjustment plate can be adjusted up and down to make the height of the suction inlet change, so as to improve the cleanness of the floor brush.