The invention discloses a variable frequency vacuum pumping environmental-protection device for a suction box. The variable frequency vacuum pumping environmental-protection device for the suction box comprises a filtering device, a variable frequency Roots vacuum device, a pressure balance valve and a silencer; one end of the filtering device is connected with a carrier roller machine through an air suction pipeline, and the other end of the filtering device is connected with a micro-spraying nozzle arranged on an air inlet of the variable frequency Roots vacuum device, through a valve; an air exhaust of the variable frequency Roots vacuum device is connected with the silencer used for reducing the noise through the pressure balance valve; and the filtering device, the variable frequency Roots vacuum device, the pressure balance valve and the silencer are all arranged in a silent case capable of absorbing a fundamental frequency harmonic wave to form the integrated environmental-protection device. The silent case can reduce the instantaneous vibration amplitude of the device, the noise is reduced to be lower than 72 decibels, the pumping speed of the variable frequency Roots vacuum device is high and is not affected by the environment temperature, and the vacuum pumping speed of the suction box is increased; the high pumping speed of the device improves the working efficiency, the installation power can be reduced to 50%-60% that of the traditional equipment, and the device protects the environment and saves the energy.