Pulmonary alveolar proteinosis(PAP)is a rare progressive respiratory dysfunction disease of the lung characterized by insidious onset and non-specific clinical manifestations,often leading to misdiagnosed and mistreated.Herein,we reported a case of PAP patient admitted to Jiading District Central Hospital with an atypical appearance of alveolar lavage fluid and whose condition improved significantly after treatment with subcutaneous injection of recombinant human granulocyte-macrophage colony stimulating factor(GM-CSF).Additionally,we have reviewed and summarized the relevant literature to enhance the understanding of the diagnosis and treatment of this disease.