To provide a compressed air injection device using an air amplifier.

The compressed air injection device using the air amplifier is configured that a compressed air supply conduit is divided into two branch pipes, the air amplifiers are connected to the upper parts of the branch pipes, and a larger amount of surrounding air is equally supplied to a bag filter at a faster speed by the pressure of air amplified in the air amplifier without an obstacle of surrounding equipments, so that a high dedusting effect can be achieved.