The three-year-old child’s two legs tight and forceful situation is considered to be related to the leg-wiping syndrome, holding urine and other factors. Leg rubbing syndrome belongs to a kind of children’s motor behavior disorder disease, belongs to the psychological behavior abnormality, at present the cause of the disease is not yet clear, the clinical manifestation of the lower limbs straighten and cross, force, clamping and other leg rubbing action. So the three-year-old child appeared two legs tight and forceful situation, do not rule out is due to leg rubbing syndrome and other factors, can be given psychological and behavioral guidance and other methods to ease. In addition, the situation that causes the three-year-old child’s two legs to be tight and forceful can not be ruled out due to the holding of urine, in the case of a sufficient bladder, the child will have the phenomenon of urination. In the case of urine can not be discharged, it can be called holding urine, so the child will use the two legs tense and forceful way, to prevent the performance of peeing pants. Three-year-old child two legs tight and hard, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.