<p>Liquid nitrogen assisted abrasive suspension jet (LN₂-ASJ) is a combined machining method of cooling before cutting, which can greatly improve the efficiency of ASJ machining tungsten steel. The reduction in machining temperature changes the physical properties of the material, thereby affecting the fracture mode. This paper took YG8/YG20 tungsten steel as the research object, analyzed the failure process at low temperatures, established a mathematical model of the distribution of fracture modes. The research results showed that when cutting tungsten steel at different temperatures by LN₂-ASJ, different proportions of ductile fracture area and brittle fracture area will form on the cutting section. Ductile fracture is dominated by yield failure, and brittle fracture is dominated by crack propagation caused by impact load. Ductile fracture area is always formed in the initial cutting stage, and brittle fracture area is easily formed when the kerf depth is large or the temperature is low. YG8 is more likely to be in the not completely cut through state and always occurring brittle fracture at a smaller kerf depth than YG20 under the same experimental conditions. At room temperature, the cutting section of YG20 may exhibit a pure ductile fracture state.</p>