Atlantoaxial subluxation must be differentiated from Meniere’s syndrome, trigeminal neuralgia, cerebral bridge, cerebellar horn lesions, acute ischemic cerebrovascular disease and limited cerebral infarction. 1. Meniere’s syndrome: It is an accumulation of water in the vagus of the inner ear membrane and manifests as episodic vertigo, fluctuating hearing loss and tinnitus. It is characterized by the onset of vertigo after the aggravation of tinnitus and the gradual reduction or disappearance of tinnitus after the onset of vertigo. Otolaryngology can assist in the diagnosis. 2. Trigeminal neuralgia: The recurrent paroxysmal transient severe pain in the distribution area of the trigeminal nerve without accompanying destruction of trigeminal nerve function is called trigeminal neuralgia. It is a sudden onset of severe pain, and the patient often presses or rubs the diseased side to relieve the pain during the attack, and in severe cases, it may be accompanied by reflex convulsions of the muscles on the same side. 3.Pontocerebellar and cerebellar horn lesions: manifesting as vertigo and progressive hearing loss on one side, unstable walking, occupying lesions at the lateral pontocerebellar and cerebellar horn can be seen on CT or MRI examination, and X-ray radiographs can show enlarged auditory canal on the side of the disease and no misalignment of the atlantoaxial spine in the open mouth position. 4, acute ischemic cerebrovascular disease: acute ischemic cerebrovascular disease is also clinically known as transient cerebral ischemic vascular disease, mostly seen in middle-aged patients, the symptoms appear in 2 minutes during the attack, but mostly recover within 15 minutes, without sequelae. It manifests as muscle weakness, paralysis, tingling sensation in the contralateral limb or face, or loss of sensation and dysarthria; or sudden vertigo, or perioral tingling sensation, abnormal sensation in bilateral limbs, or ataxia. 5.Limited cerebral infarction: Stroke (commonly known as “stroke”), mostly in middle-aged or older patients with hypertension, diabetes, heart disease or hyperlipidemia, showing symptoms such as one-sided headache, vertigo, vomiting, abnormal sensation on the opposite side of the body, hemiparesis, slurred speech, etc. CT and MRI examinations can assist in the diagnosis.