Knee pain when squatting but not when walking can be caused by the following reasons: first, patellofemoral joint disease, when the patellofemoral joint has patellofemoral arthritis, there can be knee pain when squatting, this is due to the patellofemoral joint cartilage damage caused by friction pain when squatting, then check the patellofemoral joint of the X-ray film, magnetic resonance to diagnose. Secondly, meniscus injury of knee joint, when there is a tear in the posterior horn of meniscus of knee joint, there can be pain when squatting due to the extrusion of the posterior horn of meniscus, which should be examined by the MRI of meniscus for diagnosis and treatment. Third, ligament injury around the knee joint, when the patellar ligament around the knee joint, quadriceps tendon and goosefoot injury, there can be squatting pain in the knee joint, this time to early checkup, check the ligament of the MRI, early physiotherapy and closed treatment.