The invention discloses a method for preparing quinolones compound by using pentacarbonyl iron as a CO release source. In this method, iron pentacarbonyl is used as a CO release source, and palladiumacetate is used as a catalyst, potassium phosphate and piperazine are used as a base, and acetonitrile is used as a solvent to couple a 2-iodoaniline compound with a terminal alkyne under mild conditions to obtain the quinolones compound. The preparation method has the advantages of simple operation, mild reaction conditions, less catalyst use, less CO release source use, low toxicity, lower cost,wide substrate applicability, and high target compound yield, and the method can be widely used for the preparation of natural quinolones compound.