In a complete mining process, the stress of bucket tooth working face is different in different working stages.When the tooth tip contact the material surface for the first time, because of its high speed, the tooth tip part of bucket tooth is strongly impacted.When the yield strength of bucket teeth is low, plastic deformation will occur on the top.With the increase of digging depth, the force on bucket teeth will change.When the bucket tooth cutting material, due to the relative movement of the bucket tooth and the material, the surface of the bucket tooth produces greater positive extrusion pressure, so that the bucket tooth working face and the material produce greater friction.If the material is hard stone, concrete, etc., the friction will be great.The repeated action of this process makes the working face of the bucket tooth and the working face produce different degrees of surface wear and tear, so as to produce a deep furrow.The positive pressure and positive pressure of the front working face are obviously larger than that of the rear working face.It can be judged that positive pressure and friction are the main external mechanical factors leading to the failure of bucket teeth and play an important role in the failure process.Therefore, the composition of bucket teeth affects the service life of bucket teeth.