Normal muscle tone is the key to maintaining coordination of body movements, and dystonia in children with cerebral palsy is a group of syndromes in which excessive muscle contraction causes persistent twisting or postural abnormalities in part or all of the body. It is an extrapyramidal disorder mainly characterized by slow, continuous, strong twisting involuntary movements of the proximal muscles of the neck, face, trunk and extremities. The symptoms are exacerbated during exercise, and in severe cases, abnormal muscle activity occurs even when the patient is quiet; there is a selective lack of muscle activity during exercise, and the completion of the movement is affected by excessive activity of unrelated muscles in the distant area. If the child has an abnormal birth history, such as asphyxia, umbilical cord encirclement, meconium amniotic fluid, premature birth, etc., it is more important to consider the possibility of abnormal brain development or original brain injury. Children with cerebral palsy often have abnormal muscle tone, which is mainly characterized by increased, decreased or shaky muscle tone. When muscle tone is increased, the muscles are stiffer, the resistance to passive movement increases too much, and the range of joint movement is reduced. Decreased muscle tone is characterized by sluggish and soft muscles, reduced resistance to passive motion, and an increased range of joint motion. The waviness of muscle tone refers to the fact that the muscle tension is completely normal when the child is quiet, but increases significantly during casual motor muscle activity, changing back and forth from low tension to high tension. The developmental process of myotonia shows an increase in flexor tone during the neonatal period and a gradual decrease in tone to normal as the child grows older. Therefore, in some less severe spastic cerebral palsy, the increased muscle tone is not obvious within 6 months of age, which sometimes causes diagnostic difficulties. However, some children with severe spastic cerebral palsy may still show increased muscle tone up to 6 months of age. Spastic cerebral palsy is characterized by increased muscle tone in the form of a “folding knife”, but it is important to note that if the limb is repeatedly flexed and extended several times, the “folding knife” sensation will gradually become less pronounced during the examination. The tardive dyskinesia type is often absent within the first year of age, but increases with age and is often “cogwheel-like” or “lead tube-like”. The ankylosing type shows increased muscle tone in the form of a “lead pipe”. The ataxic type does not have increased muscle tone, while the hypotonic type shows low muscle tone, increased joint range of motion, but active or hyperactive tendon reflexes. 1, muscle tone is the tension of the muscle in the quiet state, by passively flexing, straightening, rotating the limb forward and backward, to understand its muscle tone. Small infants can hold their forearms and shake their hands to understand the muscle tone of the upper limbs according to the range of motion of the hands. Measure the muscle tone of the lower limbs can also hold the lower leg and shake its foot, according to the range of foot activity to judge its tension, tension is low when shaking hands and feet when the range of hand and foot shaking, tension is high when the range of activity is small. 2, can be judged according to the size of the joint range of motion, passive movement of the joint if the range of motion is large, indicating low muscle tone, joint range of motion is small, limited activity indicates high muscle tone. To understand the range of motion of the shoulder joint of the upper limb, we can check the “scarf sign” and observe the relationship between the elbow joint and the midline of the trunk; to understand the muscle tone of the lower limb, we can check the abduction angle, the rouge fossa angle, the heel touch test and the dorsiflexion angle of the foot. 3, check muscle tone can also be understood through the “pull test”, this test is easy to grasp, hold the child’s hands, pull them from the supine position into a sitting position, observe the head hanging back to understand the muscle tone of the back of the neck. When examining muscle tone, it is important to note that some older children with a longer course of disease have joint contractures that limit joint movement, so do not mistake this for increased muscle tone. Abnormal muscle tone in babies must be closely monitored by mothers and fathers, and once abnormalities are detected, they should be seen in the hospital in time. If the abnormal muscle tone is caused by cerebral palsy, the root cause of the disease is brain damage, and it is difficult to improve the muscle tone simply by rehabilitating and massaging. The child’s disease is in the brain, so the damaged brain cells must be repaired at the source, and then the limb training must be carried out to combine the treatment of brain and palsy in order to completely improve the muscle tone.