The invention relates to a milling cutter mechanism. The milling cutter mechanism comprises a seat, a drive assembly and a milling assembly, wherein the seat comprises a base, two cross beams and an installation beam; the two cross beams are arranged on the base at an interval; the drive assembly comprises an installation block, a lifting cylinder, a slide block and a drive element; a plurality of installation grooves are formed in the installation beam; the milling assembly comprises a main shaft and a milling cutter connected to the main shaft; and the main shaft is connected to the drive element. A dust blowing assembly is arranged on the base, the dust blowing assembly comprises a dust blowing air pump, a dust blowing frame and a dust blowing tube, the dust blowing frame forms a working space in a surrounding manner, the dust blowing tube communicates with the dust blowing air pump and the dust blowing frame, and a plurality of dust blowing holes are formed in the dust blowing frame. The milling cutter mechanism is more convenient in chip removal and capable of ensuring the machining accuracy.