For meniscus injury with knee effusion, you can go to the orthopedic department to see a doctor first. The doctor can make a preliminary determination of the degree of meniscus injury and the amount of effusion with the physical examination, and further improve the knee MRI to make a more accurate judgment. For less serious meniscus damage and small amount of fluid, you can try conservative treatment first, you can take oral medication to activate blood circulation and resolve blood stasis, such as blood circulation and pain capsules. The other thing is to pay attention to rest and recuperation, try to avoid long distance walking, excessive knee flexion. If there is no obvious effect, if there is still obvious pain, or if the MRI examination itself belongs to the third degree of injury, and there is obvious effusion, arthroscopic treatment can be considered, such as arthroscopic meniscus repair or partial resection and shaping surgery.