An inflatable charging device applied to a shoe, wherein the shoe comprises a shoe body and a bottom part connected to the shoe body, such that a wear space and an opening communicated with the wear space are collaboratively defined by the shoe body and the bottom part, the inflatable charging device comprising: an inflatable cushion disposed in the shoe body; an air passage arranged between the inflatable cushion and the shoe body and in air communication with the inflatable cushion; an air pump communicated with the air passage; a weight sensor disposed on the bottom part; an air pressure sensor disposed in the air passage; a control module electrically connected with the air pump, the weight sensor and the air pressure sensor; and a charging power source for charging an external electronic device, the charging power source is embedded in the bottom part and electrically connected with the control module, wherein the charging power source comprises a pressing plate, a pressure electric generator, a rechargeable battery, and a power source output port, wherein a first end of the pressing plate is pivotally connected with the pressure electric generator, and a second end of the pressing plate is disposed on the bottom part to be pressed by a foot of the user by which the pressure electric generator generates electric power, wherein the rechargeable battery is used for storing the electric power generated by the pressure electric generator and providing the electric power to the control module, and wherein the power source output port is connected with the electric power outputted from the rechargeable battery for charging the external electronic device; wherein when the weight sensor detects a load, the weight sensor sends an enabling signal to the control module, and the control module drives the air pump to operate according to the enabling signal, making air guided by the air passage and introduced into the inflatable cushion, so that the inflatable cushion is inflated and expanded, wherein when the air pressure sensor detects the pressure inside the inflatable cushion is higher than a specific threshold interval, the air pressure sensor sends a disabling signal to the control module and the control module accordingly stops the operation of the air pump. an inflatable cushion disposed in the shoe body; an air passage arranged between the inflatable cushion and the shoe body and in air communication with the inflatable cushion; an air pump communicated with the air passage; a weight sensor disposed on the bottom part; an air pressure sensor disposed in the air passage; a control module electrically connected with the air pump, the weight sensor and the air pressure sensor; and a charging power source for charging an external electronic device, the charging power source is embedded in the bottom part and electrically connected with the control module, wherein the charging power source comprises a pressing plate, a pressure electric generator, a rechargeable battery, and a power source output port, wherein a first end of the pressing plate is pivotally connected with the pressure electric generator, and a second end of the pressing plate is disposed on the bottom part to be pressed by a foot of the user by which the pressure electric generator generates electric power, wherein the rechargeable battery is used for storing the electric power generated by the pressure electric generator and providing the electric power to the control module, and wherein the power source output port is connected with the electric power outputted from the rechargeable battery for charging the external electronic device; wherein when the weight sensor detects a load, the weight sensor sends an enabling signal to the control module, and the control module drives the air pump to operate according to the enabling signal, making air guided by the air passage and introduced into the inflatable cushion, so that the inflatable cushion is inflated and expanded, wherein when the air pressure sensor detects the pressure inside the inflatable cushion is higher than a specific threshold interval, the air pressure sensor sends a disabling signal to the control module and the control module accordingly stops the operation of the air pump.