本文对１４例肺部呈弥漫性病变的恶性肿瘤误诊原因进行分析。误诊为血行播散型肺结核９例，肺结核支气管播散者２例，支气管肺炎２例，矽肺１例。对肺癌早期症状警惕性不高，忽视对青年人肺癌的警惕，对肺结核瘢痕发生癌变或肺结核与肺癌并存认识不足，只注意到Ｘ线某一特征而忽视结合临床全面分析，忽视肺转移癌的发生，只注意职业史而忽视鉴别诊断是造成误诊主要原因。 This article analyzes the causes of misdiagnosis of 14 malignant tumors with diffuse lung lesions. Misdiagnosed as 9 cases of hematogenous disseminated tuberculosis, 2 cases of tuberculosis bronchial disseminated, 2 cases of bronchial pneumonia, 1 case of silicosis. The early symptoms of lung cancer are not vigilance, ignore the vigilance of lung cancer in young people, and there is insufficient understanding of the occurrence of cancerous tuberculosis or pulmonary tuberculosis and lung cancer. They only pay attention to a certain feature of X-ray and ignore the comprehensive analysis of clinical features, ignoring the metastasis of lung cancer. Occurrence, only pay attention to professional history and ignore the differential diagnosis is the main cause of misdiagnosis.