GH4169 alloys are important end component materials for aerospace engines. When serving in a high-temperature and oxygen-rich environment, metal combustion is prone to occur, resulting in catastrophic accidents. On the basis of the self-developed experimental equipment for the oxygen-enriched combustion of metal materials, the flame retardancy and combustion behavior of the GH4169 alloy prepared by selective laser melting were studied, which is highly important for its use at high temperatures. The microstructure of the as-built GH4169 alloy shows a typical fish-scale morphology. The grain texture is oriented mainly in the <001> direction and generates columnar crystals that grow across multiple molten pools. The precipitated phase is mainly the island-chain Laves phase, which precipitates at the grain boundaries and interdendrites. The combustion results show that the burning pressure threshold of SLM-GH4169 is approximately 3.7 MPa under 99.5% pure O2 ignition at room temperature, which is equivalent to the flame retardancy of the forged GH4169 alloy. The analysis of the morphology of the combustion zone revealed that Al, Ti, Nb and other elements are flammable, and many of these elements participate in combustion to form oxides. Ni does not burn easily and is enriched in the melting zone. Many holes are observed in the heat-affected zone, which are caused by the melting of the Laves phase. Because the Laves phase is rich in high-combustion calorific value elements such as Nb and Ti and has a low melting point, it will preferentially melt compared with the matrix and participate in burning during combustion, which is very  unfavourable to the flame retardancy of the alloy. Therefore, to improve the flame retardant properties of the alloy, it is necessary to improve the laser selective melting process and formulate a reasonable heat treatment system to eliminate the Laves phase.