The invention relates to a 
halogen-free environment-friendly 
flame-retardant 
polyolefin master batch for replacing 
bromine-containing 
flame retardant and a preparation method of the master batch. The master batch is prepared from, by weight, 90-100 parts of carrier resin, 200-420 parts of 
halogen-free 
flame retardant, 1.5-3 parts of a cladding treatment agent, 65-100 parts of a synergistic agent and 0.1-0.5 part of 
antioxidant. The preparation method comprises the steps of sufficiently treating the 
halogen-free flame retardant with the cladding treatment agent, then uniformly mixing the halogen-free flame retardant with the carrier resin, the synergistic agent and the 
antioxidant, then conducting extraction through a double-screw extruder or a mixer, and 
cutting the product into granules, so that the halogen-free environment-friendly flame-retardant 
polyolefin master batch is obtained. Compared with the prior art, the product prepared through the preparation method has more excellent flame retardancy, 
environmental protection performance and processability, is free of 
corrosion or 
precipitation and resistant to high temperature and 
high humidity, has universality and is quite applicable to shells of small household appliances and electronic and electric products, shells of printed circuit boards, shells of motors, shells of 
electric control centers and the like.