SIM (subscriber identity module) card hot swapping circuit and mobile phone thereof

The utility model discloses an SIM (subscriber identity module) card hot swapping circuit and a mobile phone thereof. The circuit comprises a baseband chip, an SIM card connector, a switch, a field-effect tube, a first partial pressure module and a second partial pressure module, wherein the switch is arranged in the SIM card connector. A source of the field-effect tube is connected with a VSIM (visual subscriber identity module) pin of the baseband chip, a drain of the field-effect tube is connected with a VSIM pin of the SIM card connector, and a grid of the field-effect tube is connected with an SIMDET pin of the baseband chip through the first partial pressure module and connected with the VSIM pin of the baseband chip through the second partial pressure module. Resistance of the first partial pressure module is smaller than that of the second partial pressure module. The switch arranged in the SIM card connector is used for detecting whether an SIM card is inserted or not, whether the SIM card connector of the baseband chip is on or not is judged according to the voltage of each pin of the field-effect tube, and thereby the SIM card can be effectively protected from being damaged by hot swapping.