The work aims to study the thermal shock resistance and antioxidant properties of thermal sprayed 20%NiCr-80%Cr3C2 coating on 5CrNiMo die steel substrate for hot die with low operating temperature (below 550 ℃). The 20%NiCr-80%Cr3C2 coating was produced on 5CrNiMo die steel substrate by high velocity oxy-fuel (HVOF). The hardness and bonding strength of the coating were tested by Vickers microhardness tester and universal mechanical testing machine. The anti-cyclic thermal shock properties of the coating between 250 ℃ and 550 ℃ were investigated by vacuum tube furnace. The morphology, microstructure and phase composition of the coatings before and after the cyclic thermal shock test were characterized by optical microscopy, scanning electron microscope (SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD), respectively. 20%NiCr-80%Cr3C2 coating prepared by HOVF was uniform and dense, with extremely high surface microhardness (818.9HV) and bonding strength (64.0 MPa). After 200 times of cyclic thermal shock, microcracks appeared inside the coating, but were not connected to each other, and the surface of the sample still remained smooth. The carbide particles precipitated in the binding phase greatly increased the hardness of the coating (1029.0HV). The oxide layer of Fe and Cr was formed at the interface between the coating and the substrate. However, the layer reached in a stable stage when the thickness increased to 1 μm, and it was continuously dense and well bonded to the substrate and the coating, and did not show the tendency to peel off from the coating. Therefore, the 20%NiCr-80%Cr3C2 coating produced by HVOF has good anti-cyclic thermal shock properties, and can effectively improve the hardness and antioxidant properties of 5CrNiMo hot die steel working surface.