The invention belongs to the technical field of precision vibration isolation and discloses a vibration isolator with pneumatic flotation ball bearing for angular decoupling and a magnetic suspension plane for driving and positioning. A lower mounting plate and a sleeve of a vibration isolator body are supported through magnetic suspension action of a magnetic suspension plane motor, and a piston barrel and the sleeve are lubricated and supported through a pneumatic flotation surface. Angular motion freedom degree between an upper mounting plate and the lower mounting plate is decoupled through the pneumatic flotation ball bearing, and a motor, a displacement sensor, a limiting switch, a controller and a drive form a position closed loop feedback control system to precisely control relative position of the upper mounting plate and the lower mounting plate. The vibration isolator has the advantages of three-dimensional zero rigidity, high positioning precision and angular decoupling, extremely low inherent frequency and outstanding ultralow-frequency vibration isolation performance can be obtained, and accordingly the problem of high-performance vibration isolation in ultra precise measurement instruments and processing equipment, especially step scanning photoetching machines can be effectively solved.