It is not scientific to say that you can squeeze pus out of a mouth ulcer. Mouth ulcers usually do not appear pus, its surface covered with yellow material is false membrane, is not recommended to squeeze out, otherwise it will affect the healing. Mouth ulcers are diseases of the oral mucous membrane, can appear onset of severe pain, burning sensation and other symptoms. In general, in the absence of localized infections, the yellow substance on the surface of mouth ulcers is a pseudomembrane (generally formed during the interim period into the healing period), not pus, if the pseudomembrane is extruded, it is easy to stimulate the wound, which is not conducive to healing, and therefore it is not recommended to extrude the pseudomembrane. Mouth ulcers can generally be treated with vitamin C, vitamin B complex and other vitamin drugs, as well as cediriodine tablets, ciprofloxacin tablets and other tablets. In addition, it is advisable to eat a light diet and not to consume spicy, overly acidic and other irritating foods. If you suffer from mouth ulcers, you should seek medical treatment in a timely manner and do not blindly use medication on your own.