Cancerous and tuberculous pleural fluid can be differentiated by the following aspects: 1. Cancerous pleural fluid is often bloody in appearance, while tuberculous pleural fluid is often straw yellow in color. 2. To differentiate, cancerous pleural fluid often contains a large number of cancer cells and red blood cells, while tuberculous pleural fluid is mainly lymphocytes and has a higher protein content. Therefore, it is easy to distinguish between cancerous and tuberculous pleural fluid clinically, and the treatment is mainly anti-tuberculosis treatment on one hand and anti-tumor treatment on the other, using perfusion chemotherapy and systemic treatment.