The invention discloses a control circuit applied to SOI (silicon on insulator) CMOS (complementary metal oxide semiconductor) radiofrequency switches. The control circuit comprises a band-gap reference circuit, a low-dropout linear voltage regulator, an annular oscillator, voltage inverters, a non-overlapping clock circuit, a charge pump and a level switching circuit. A core unit of the control circuit is a charge pump circuit capable of generating negative voltages. The band-gap reference circuit is connected with the low-dropout linear voltage regulator, an output end of the low-dropout linear voltage regulator is connected with the charge pump, an output end of the annular oscillator is connected with an input end of the inverter I2 by the inverter I1, an output end of the inverter I1 and an output end of the inverter I2 are connected with an input end of the non-overlapping clock generating circuit, four output ends of the non-overlapping clock generating circuit is connected with an input end of the charge pump, and the SOI CMOS radiofrequency switches can be controlled by an output end OUTPUT of the charge pump via the level switching circuit. The control circuit has the advantages that the charge pump capable of generating the negative voltages can be quickly started and has low steady-state currents, accordingly, radiofrequency switch tubes can be assuredly in excellent closed states under the conditions of high radiofrequency signals, and the linearity and the isolation of the radiofrequency switches can be improved.