Special high -efficient junk mill of horizontal well relates to horizontal section milling and handles the design technical field with the junk mill. The utility model discloses a junk mill body sets up a plurality of first counter bores in junk mill body bottom, sets up the tungsten alloy post in every first counter bore respectively, set up a plurality of basins in junk mill body bottom, this internally sets up a plurality of hydrophthalmias at the junk mill, every hydrophthalmia one end respectively with junk mill body inner chamber intercommunication, the other end feeds through with the basin that corresponds, set up a plurality of second counter bores in junk mill body periphery, can the roll formula set up the steel ball through the clamp plate in every second counter bore, the clamp plate passes through bolt and junk mill body fixed connection. The utility model has the advantages of simple and reasonable structure, efficient, not fragile, convenient to use.