The invention relates to a supercharging device and a supercharging method for low-temperature 
rocket ground redundancy. The device comprises 
pilot-operated type two-bit two-way normally closed solenoid valves, a two-bit three-way 
solenoid valve, manual stop valves and restriction orifices arranged on a low-temperature propellent supercharging gas source gas inlet pipeline; the second 
pilot-operated type two-bit two-way normally closed 
solenoid valve and the third 
pilot-operated type two-bit two-way normally closed 
solenoid valve are started, and tank pressurization is rapidly conducted by gas which passes through the second restriction orifice and the third restriction orifice. According to the supercharging device for the low-temperature 
rocket ground redundancy, the single-point problem of a low-temperature propellent 
rocket ground electric supercharging gas circuit is solved, it is guaranteed that a target requirement of narrow window launching is met, four independent solenoid valves are adopted to achieve a series-parallel connection redundant 
backup, by means of the restriction orifice with different hole diameters, rapid and high-precision supercharging before launching is guaranteed, and the reliability of the rocket launching is improved.