An embodiment of the invention discloses a voltage dropping converter, a voltage dropping method, a device and a system thereof. The voltage dropping converter comprises a first voltage dropping unit,a second voltage dropping unit and a DC supporting capacitor unit, wherein the first end of the first voltage dropping unit is connected with a positive voltage input end. The second end of the firstvoltage dropping unit and the first end of the second voltage dropping unit are respectively connected with one end of the DC supporting capacitor unit and the positive voltage output end. The thirdend of the first voltage dropping unit and the second end of the second voltage dropping unit are respectively connected with the other end of the DC supporting capacitor unit and the negative voltageoutput end. The third end of the second voltage dropping unit is connected with the negative voltage input end so that voltage between the positive voltage output end and the negative voltage outputend is lower than voltage between the positive voltage input end and the negative voltage input end. The voltage dropping converter, the voltage dropping method, the device and the system thereof haveadvantages of improving voltage dropping efficiency and reducing cost of the voltage dropping converter.