The invention provides a method for producing liquid carbon oxide. The method comprises an expanding step, a first gas-liquid separating step, a liquefying step and a heat exchange step. The method disclosed by the invention can be used for treating carbon dioxide raw material gas flow, especially the carbon dioxide raw material gas flow with relatively high carbon dioxide concentration (for example, the concentration of carbon dioxide is over 70mol%), obviously increasing the yield of the liquid carbon dioxide, lowering the production cost of the liquid carbon dioxide and improving the overall yield of the process.