TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preparation: Preparing hydrogen using arc H2C compound universal fuel comprises (a) injecting nitrogen into the arc H2C compound universal fuel hydrogen manufacturing reactor inside the device, and then air the reactor will be sucked to be vacuum for three times, and then the remained nitrogen will be pumped out after the reactor is fully filled with water, and then the two electrodes inside the reactor will be buried 0.4 to 0.6 meters below water under vacuum, and then rectifying control device will be used to exert voltage onto the two electrodes, and at the same time, the two electrodes are adjusted via the electrode control device to cause a degree with 45 to 90 degrees between the opposite points of them; when distance between the two electrodes discharging end is up to 1 to 3 millimeters, the two electrodes will be caused to form arc discharging, and plasma reaction under non-equilibrium state; (b) collecting generated arc H2C compound universal fuel gas bubble during reaction, and they are made to go through a transporting pipeline to the condenser to be cooled and dried, and then the arc H2C compound universal fuel is picked up; (c) after the arc H2C compound universal fuel obtained in (b) is filtered by filter device, they will be transported to a storing device, and then the arc H2C compound universal fuel is obtained; (d) filtering by filter device in (c) involves using carbon molecular film to filter out component like carbon dioxide (CO2) and carbon monoxide (CO), and changing the left arc H2C compound universal fuel into pure hydrogen after filtering by metal palladium membrane, and then it will be output after processed by low-pressure compressor. Preferred Components: Arc H2C compound universal fuel hydrogen manufacturing reactor (3) is composed of carbon electrode, tungsten electrode, or twin-carbonic electrode working resistor RL1 and RL2 and reactor main body. Rectifying control device (3) is composed of electricity control cabinet and rectifier. Condenser (7) is a cold-dry machine. Preferred Device: The carbon electrode utilizes carbon rod electrode, which is firmly contacted with its inner cavity, to be equipped inside copper conducting frame; discharging ends of carbon electrode and tungsten electrode are oppositely equipped to be as voltaic arc generating end; container for containing water is equipped inside the reactor main body (21), the voltaic arc discharging ends (22) of the two electrodes are equipped inside the reactor main body (21); the carbon electrode is connected with electricity output end of the rectifying control device (2); the tungsten electrode is connected with the other end of the electricity output end of the parallel connected working resistor RL1 and RL2 with the rectifying control device (2). Dynamic electric source is connected with the rectifier via the electric source control cabinet; electricity output end of the rectifier is respectively connected with the two electrodes inside the arc H2C compound universal fuel hydrogen manufacturing reactor (3). The filter device (8) is equipped inside the low-pressure compressor; gas outlet if the filter device is connected with the low-pressure gas storing tank that is used as low-pressure storing device (9); gas use opening is equipped in the low-pressure gas storing tank for supplying fuel gas to the outside.