Differential diagnosis of submandibular gland tumor includes cyst of sublingual gland, vascular malformation and metastatic cancer. 1. Sublingual gland cyst: clinically, it manifests as enlargement of submandibular gland, which may appear thick, slightly yellow or egg white-like fluid, but the cause of the disease is actually in the oral cavity, and the surgical treatment is also operated in the oral cavity, not in the submandibular gland. 2. Vascular malformation: the malformation of blood vessels in maxillofacial area may also cause enlargement of maxillofacial area, which usually only needs to be treated with medicines and does not need to be operated. 3. Metastatic cancer: for example, mandibular gingival cancer can lead to enlargement of maxillofacial area by submandibular and sub-chin lymph nodes, which needs surgical treatment and radiotherapy. If the swelling of submandibular gland appears, one should go to regular hospital for consultation in time.