A new NC bi rotary three spindle parallel type rotary table was introduced.It had three parallel rotary spindles mounted in a housing. A motor drove three parallel spindles to rotate synchronously by a bevel gear and two cylindrical gears and idle gear, another motor drove rotary table to rotate by a pair of worm gear and worm. The rotation range of A-axis (around the x-axis rotation) is 0 ~ ± 90° while C-axis (around z-axis rotation) is 0 ~ ±∞. A-axis and C-axis can be controlled synchronously by NC system.