Synovitis of the knee, divided into acute and chronic, has a wide variation in recovery time, which may be about 4 weeks or may require long-term treatment. Acute synovitis of the knee, most often seen as a result of trauma, results in the accumulation of blood and fluid in the knee joint after injury and requires systematic treatment. During treatment, attention should be paid to braking the affected limb, reducing weight bearing and activity, and paying attention to keeping the knee joint warm, which generally results in a good recovery in about 4 weeks. Synovitis caused by the inflammatory stimulation of osteoarthritis of the knee joint has a high probability of becoming chronic and has a high recurrence rate, even after systematic treatment, the prognosis is poor and requires long-term treatment and the patient’s own maintenance. To recover from synovitis of the knee, it is necessary to actively search for the triggering factors and choose the right treatment plan to speed up the recovery. In addition, it is important to prevent synovitis by wearing knee pads during sports activities and exercising reasonably effectively.