To provide a method and equipment for controlling compressed air supply in a jet loom so as enable not only to maintain piping work in a small scale but also to suppress effects to a minimum even when pneumatic piping pits or pneumatic pressure lowers, so as to prevent the compressed air supply equipment from useless drive.

This method and the system therefor supply compressed air into a jet loom from a compressed air supply unit 5 installed in the jet loom through a compressed air supply line in which the compressed air pressure is detected with a pressure switch 10, and the system controls the compressed air supply unit 5 with the help of a loom control computer (C0) so that the compressed air pressure detected with the pressure switch 10 can be maintained within a preset pressure range. If during the time the jet loom remains stopped and/or is in operation, the pressure detected with another pressure switch 16 drops to a preset abnormal level outside the preset pressure range, the system drives the compressed air supply unit 5 in high rotational speed by a command of the loom control computer C0 and compensates the pressure drop.