The presence of a large and small testicle in a one-and-a-half-year-old patient is considered to be related to syringomyelia. The syringomyelia that occurs more frequently in infants is mainly a traffic syringomyelia, which means that the sheath is connected to the abdominal cavity. The scrotum enlarges when the child stands for a longer period of time and shrinks when resting flat or sleeping. Therefore, when the patient has this clinical condition, it is recommended to go to the hospital to choose the relevant examination to make a clear diagnosis, which can be done by scrotal ultrasound examination, and after the diagnosis is confirmed, it is recommended to choose surgery for treatment in time.