There are many causes of blood blisters in the mouth, the most common is traumatic mucosal blood blisters, mostly seen in patients eating hard and crunchy food scratching the palate mucosa, traumatic blood blisters, blood blisters are often large, 2~3cm in size. The pain is not obvious and there is a foreign body sensation. Mucosal blisters may also be formed when the mucosa is inadvertently bitten by chewing, often located in the corners of the mouth or the buccal mucosa, and are small, 0.5 cm in size. Generally, large blood blisters need to be seen in the mucosa department of a dental hospital or the stomatology department of a general hospital, where a sterile syringe is used to extract the blood from the blister, or the wall of the blister is punctured to release the bruised blood, and topical medications are applied to promote ulcer healing. Mucocutaneous aspergillosis is an autoimmune disease. The most common site of blistering in the oral cavity is the gingiva, with diffuse erythema at the gingival margin and adjacent attached gingiva, on which blisters of 2 mm to 6 mm in diameter are common. The herpes are clear or bloody, with a thick herpetic membrane and a white or off-white herpetic membrane visible after breaking. As the disease can occur in tissue scar adhesions, if it occurs in the uvula, soft palate, tonsils, tongue-palate arch and pharyngeal-palate arch, it is easy to adhere to the adjacent tissues, resulting in deformity. Aminophenyl sulfone is commonly used in the treatment of scar-like aspergillosis; the combination of systemic glucocorticoids and cytotoxic drugs can be considered for those with severe oral conditions or with mucosal damage in the eyes and throat. If the oral cavity is painful due to multiple erosions and affects eating, anti-inflammatory and pain-relieving rinses should be used in combination with glucocorticoid topical preparations. For specific medication, please refer to the clinical situation and be guided by the doctor’s interview.