3D building printing head with width detection and surface cleaning functions

The utility model discloses a 3D building printing head with width detection and surface smoothness functions, and relates to the technical field of 3D building printing equipment. The feeding device specifically comprises a material barrel, an auger and a feeding motor used for driving the auger to rotate, a nozzle is arranged on a discharging port of the material barrel, a rotating disc is rotationally arranged at the lower end of the nozzle, and a first driving part used for driving the rotating disc to rotate is arranged between the rotating disc and the nozzle. The rotating disc is provided with two sets of detection assemblies which are symmetrically arranged relative to a symmetric plane, and the symmetric plane passes through the axis of the nozzle. Each group of detection assembly comprises a first laser device and a second laser device, the distance between the two first laser devices is the maximum size of the allowable width of the wall body, and the distance between the two second laser devices i