Disclosed is a radio frequency switch and its radio frequency communication system. The RF switch comprises: N switch transistors Q1˜QN connected in series, wherein a first conducting terminal of Q1 serves as an output end, a second conducting terminal of QN serves as an input end a switch transistor located closer to the output end has a higher or equal withstand voltage than that of a switch transistor located closer to the input end, or a switch transistor located closer to the output end has a lower or equal withstand voltage than that of a switch transistor located closer to the input end, and Q1 and QN has different withstand voltages. The withstand voltages of the switch transistors match the voltage division situation of the switch transistors affected by parasitic effect in the RF switch, thus the voltage withstand capability is basically not affected by parasitic effect.