After the child smashed his foot, it is recommended to immediately consult a doctor to improve the X-ray examination to exclude the possibility of fracture, if there is no fracture, it can be applied externally, elevate the lower limbs, medication and other methods to reduce swelling. 1. External compresses: Usually within 72 hours after the trauma, ice can be applied to the affected area for 10 to 15 minutes each time to achieve the effect of swelling, and hot compresses can be applied after 72 hours to promote blood circulation. 2. Elevate the lower limbs: put the child on the bed and elevate the affected limbs to reduce the blood flow to the lower limbs to reduce the swelling. 3. Medication: If the pain in the affected area is obvious, topical medication such as ibuprofen can be used to relieve pain. If there is fracture damage, or swelling is obvious, it is recommended to actively seek medical advice and follow the doctor’s instructions for examination and treatment.