The rotary table bearing features a combined construction to accommodate set of radial rollers and two sets of thrust rollers. This roller bearing has an outer ring and two inner rings, applied with a preload and having mounting holes in them. The rotary table bearing simplifies the bearing construction and reduces the requirements for installation, so it is suitable for applications where high accuracy, high rigidity, combined load carrying capacity are required with low speed and short time working conditions, such as indexing table.