In this paper, the wear mechanism of harmer head and plate of coal crusher of circulating fluidized boiler(CFB) is researched. In order to extend the life of the hammer head and screen plate, some new design is advanced on material and structures. A practical instance shows that these new design can extend the life of the hammer head and screen plate and improve the working efficiency of coal crusher. Also these can reduce the lingering time of the big hard coal lump in the crusher, reform and optimize the grade ratio of the crushed coal lump. In addition these researches are meaningful for energy saving.