The Type and Precipitation Mechanism of Carbide in Co-Cr-W-Ni Alloy have significant influence on the mechanical properties of alloy.Therefore, the precipitation type, distribution characteristics and precipitation mechanism of carbides after aging of Co-Cr-W-Ni alloy were studied in this work. The ageing samples were observed by XRD, scanning electron microscopy and transmission electron microscopy. The experimental results show that the types of carbides are M₇C₃, M₆C and M₂₃C₆. M₂₃C₆ carbide preferentially precipitates at grain and twin boundaries with a cube-cube orientation relationship with the matrix. The M₇C₃ carbide decomposed gradually with the M₆C carbide precipitating in situ is an important mechanism of carbide precipitation.