Provided is an oral cavity visual detector which is convenient for doctors to go to grassroots, frontier and islands for health check-ups and to ward around. The oral cavity visual detector mainly comprises a liquid crystal display screen upper cover, a liquid crystal display screen, a liquid crystal display screen lower cover, a plastic main body upper casing, a circuit board, a plastic main body lower cover, a lithium battery, a usb interface, a power switch, a telescoping connecting line, a camera handle, a miniature camera with an led lamp, etc. The beneficial effects of the oral cavity visual detector are that the detector is 10*6cm in size, is small and delicate, is convenient to carry, needs no side lights or reflection head mirrors, and helps to change a traditional diagnosis and treatment method that a patient has to go to hospital for an oral cavity check-up, and a doctor simply views and the patient listens.