Provided is a particle pollution reducing method used for a multi-chamber plasma processing device. The plasma processing device at least comprises two chambers, and each chamber is provided with a cathode at a lower position. The cathode is connected with a radio frequency power source. Substrates are arranged on the chambers to process. The method comprises the following steps: (a) first process air is piped into the multiple chambers, and a first frequency is applied to the multiple chambers so that a plasma is stimulated to execute a first process on the substrates respectively; (c) a second frequency is applied to the chambers which complete the process first so that the plasma is maintained to be just at the no-put-out state; (e) second process air is piped into the multiple chambers, and a third frequency is applied to the multiple chambers so that the plasma is stimulated to execute the second process on the substrates respectively. Particle pollution of the plasma processing chambers can be substantially improved by the method, and stability and efficiency of the process are enhanced.