The invention provides a brush body and relates to the technical field of cleaning equipment, and the defects that a traditional brush body auxiliary air inlet is not adjustable in size and poor in applicability are overcome. The brush body provided by the invention comprises a cleaning brush body internally provided with a cavity structure, a dust suction opening is formed in the bottom surface of the cleaning brush body, an auxiliary air inlet communicated with the outside of the cleaning brush body is formed in the cavity wall of the cleaning brush body, and the brush body further comprisesan opening adjusting device used for adjusting the size of the opening of the auxiliary air inlet. The invention further provides a cleaning brush which comprises the brush body. The invention further provides a dust collector which comprises the cleaning brush. In conclusion, the opening adjusting device is additionally arranged, the size of the opening of the auxiliary air inlet can be adjustedto be suitable for different surfaces to be cleaned, and the applicability is greatly improved.