The invention provides a radio-frequency (RF) power supply device provided with a multi-way output synchronizing signal source, power amplifiers, matchers and discharging electrodes. The output of each matcher is connected and matched with the discharging electrode; the input of each matcher is connected and matched with the output of the power amplifier; the outputs of the multi-way output synchronizing signal source are synchronously amplified by a plurality of ways of power amplifiers under the power supply action of a direct current power source; the RF discharge of a plurality of ways ofdischarging electrodes to gas is carried out under the joint action of a plurality of ways of matchers so that the gas in a plurality of ways of discharging electrodes generates glow. The gas produces plasma, generates laser in a laser resonant cavity and adopts a radio RF motivation mode; the RF electrodes are arranged outside the resonant cavity without contacting with the discharged gas; the RF is from 10 thousand to 3 million MHz; and ionization and discharge are carried out by the isolation of the gas in a glass motivation cavity so as to avoid polluting the resonant cavity and optical devices by the sputtering and the erosion of the electrodes.