The3-row roller slewing bearing consists of three seat rings. The upper, lower and radial roller path are separated, which makes it easy to determine the load on each row of roller. It can bear all kinds of load and has the biggest bearing capacity among the four kinds of products. It has firm structure and larger axle and radial size, which is especially applicable to heavy machinery that requires larger diameters, such as bucket wheel excavators, wheeled crane, marine hoist, ladle swing table and large tonnage truck crane.