The disclosure discloses a cutterhead assembly of a branch grinder, including a cutterhead body, a center shaft disposed in a center of the cutterhead body and at least two installing shafts circumferentially distributed by using the center shaft as an axis, each of the at least two installing shafts is successively provided with a limiting plate, a first blade, a first bush, a second blade and a second bush from top to bottom, the first blade and the second blade are in clearance fit with a corresponding installing shaft in the at least two installing shafts, a center of the limiting plate is positioned at an upper end of the center shaft and a gap is kept between the limiting plate and an upper end of the first blade, an outer end of the limiting plate is stretched into the installing shafts and fixed, through the above installation, the first blade and the second blade can be completely rotated in 360 degrees relative to the installing shafts, in a circumferential rotating process of the blade, shredded wood can be taken out from the center of the cutterhead body, and a problem, that material blockage is caused to affect a cutting effect of the cutterhead assembly due to the material is stacked in the center of the cutterhead body 1, is avoided.