The invention relates to a medical cotton swab soaked by preloaded normal saline, which comprises a sleeve rod, a telescopic rod, a storage cylinder and a transparent protective sleeve, a storage groove is formed in the inner bottom end of the sleeve rod, and the telescopic rod is arranged in the storage groove. The medical cotton swab has the beneficial effects that by arranging the telescopic rod, the sleeve rod, the internal thread and the external thread, the length of the medical cotton swab can be adjusted according to actual use requirements, the situation that in the wound cleaning process, due to the fact that the cotton swab is too short, operation of medical staff is inconvenient is effectively avoided, and the use efficiency of the cotton swab is improved; by arranging the storage cylinder, a storage cavity, a sealing plug and a connecting table, normal saline can be stored on the medical cotton swab, the medical cotton swab can be conveniently and rapidly wetted in the using process, time consumed for additionally searching for the normal saline is saved, and the wound cleaning efficiency of a patient is improved.