Iron-based matrix composites was prepared by powder metallurgy for short carbon fiber reinforced diamond bit, based on the analysis on the influence on the sintering properties of composites with different carbon fiber addition quantity, the influence laws of short carbon fiber on the properties of iron-based matrix materials under this experimental preparing conditions were obtained. On the basis of the discussion on these laws, the possibility of more excellent short carbon fiber reinforced iron-based matrix composites developing is put forward.