Abstract: The effects of CaB₆ content in flux cored wire on microstructure, phase, hardness and wear resistance of surfacing metal on Q235 steel plate were studied. The results show that the surfacing layer is mainly composed of austenite, martensite, eutectic carbon boride and carbon boride, and with the increase of CaB₆ content, the number of white carbon boride blocks in the matrix gradually increases; that the surfacing layer with 6.0% CaB₆ is mainly composed of Cr-Fe, (Cr, Fe) ₇ (C, B) ₃, (Cr, Fe) ₃ (C, B), austenite and martensite, and the width of the fusion zone is about 18 μm with a strong interface; that with the increase of CaB₆ content, the average hardness of surfacing layer shows a gradually increasing trend, while the relative wear resistance increases first and then decreases, and it reaches the maximum when the amount of CaB₆ is 3.0%.