In this paper, a type of high efficient ultra-thick high-chromium cast iron surfacing flux-cored wire with a diameter of 6mm is designed. To solve the technological problem that the processing property of ultra-thick flux-cored wire can not satisfy the welding requirement, the author adopted “inter twist connection” and “inner wire” technologies. The effect of B on the microstructure and property of deposited metal was investigated by means of optical microscopy (OM), X-ray diffraction (XRD) and abrasion test. The test of engineering application was carried out on sinter raw material transport system in steel enterprises. It is proved that the welding efficiency and the service life of wear-resistant parts are significantly improved. The ultra-thick high-chromium iron surfacing flux-cored wire has a wide application prospect.