The utility model relates to a roller bit for strengthening flow passage, belonging to the tools technical field for geological drilling and oil drilling. The utility model has the following technical proposal: the utility model comprises a roller cone and a palm, wherein the roller cone is connected to the palm through a palm axle journal; a flow passage is arranged inside the palm and is connected with the water hole and the difference is that the end of the flow passage and the water inlet is welded with erosion resistance layer made of nichrome powder. Compared with the prior art, this utility model has the advantages of that the palm flow passage is more erosion-resistant than the cementite surface and the plated surface and can complete the drilling operations with the combined nozzle under the conditions of high pump pressure and large discharge, thereby improving the work efficiency of the roller bit. This utility model is characterized in that the combination of the erosion resistance layer with the base is metallurgically considered as a part of group, and the binding force is stronger than that of the adherence between the painting layer and the base, thereby the service period is prolonged.