Pneumatic brake device, control method thereof and motion platform

The invention provides a pneumatic brake device, a control method thereof and a motion platform. The pneumatic brake device includes: a base configured to be connectable with a mobile station; an elastic member; the pneumatic structure has a floating state and a braking state and comprises an air cushion, the first face of the air cushion is constructed to be capable of being aligned with the fixing table, the elastic piece is arranged between the second face of the air cushion and the base, the air cushion is provided with a positive pressure connector and a positive pressure air outlet hole which are communicated with each other, and the positive pressure air outlet hole is inwards formed along the first face of the air cushion; the positive pressure interface is configured to be capable of communicating with a positive pressure air source; in the braking state, the positive pressure air source is closed, and the elastic piece enables the first face of the air cushion to abut against the fixing table under