NOVELTY - Water fuel system comprises anode and cathode fixers (66, 84), water electrolyzer (50), cooling device (90), and water tank (80). The anode and cathode fixers are connected with anode and cathode of electric source (71), respectively. The water electrolyzer comprises long-cylindrical outer shell, anode spliced mouth piece, cathode spliced mouth piece, sleeve body, and bar body. The anode spliced mouth piece is fixed to the anode fixer. The sleeve body is fixed to the anode spliced mouth piece and electrically connected with it.    USE - Water fuel system for supplying mixed gas of hydrogen and oxygen (claimed).    ADVANTAGE - The water fuel system has high hydrogen producing efficiency and is economic and environment friendly.    DETAILED DESCRIPTION - Water fuel system comprises anode and cathode fixers, water electrolyzer, cooling device, and water tank. The anode and cathode fixers are connected with anode and cathode of electric source, respectively. The water electrolyzer comprises long-cylindrical outer shell, anode spliced mouth piece, cathode spliced mouth piece, sleeve body, and bar body. The anode spliced mouth piece is fixed to the anode fixer. The sleeve body is fixed to the anode spliced mouth piece and electrically connected with it. The anode spliced mouth piece is fixed to one end of the outer shell in an insulated way and places the sleeve body in the outer shell. The cathode spliced mouth piece is fixed to the cathode fixer. The bar body is fixed to the cathode spliced mouth piece and is electrically connected with it. The cathode spliced mouth piece is fixed to one end of the outer shell and places the bar body in the sleeve body. The bar body is distant from the sleeve body. The upper part of the water tank is set with air outlet opening while the lower part of the water tank is connected with water inlet of the cooling device. The anode spliced mouth piece is connected between the air outlet opening of the water tank and the cooling device. The water inlet of the cooling device is connected to the cathode spliced mouth piece. The anode and cathode spliced mouth pieces are connected with the outer shell through internal and external screw threads. The outer shell is cylindrical and set with through-hole along its axial direction. The anode and cathode spliced mouth pieces are set with through-holes connected with the through-hole of the outer shell. The sleeve body is spiral spring wound by titanium strand. The bar body is made of titanium material and held in sleeve hole at the middle part of the spiral spring. The cathode spliced mouth piece is conducted with the outer shell. The water tank comprises main water tank and auxiliary water tank connected near the bottom, and air exit hole. The air exit hole is set at the top part of the auxiliary water tank. The anode spliced mouth piece is connected to the upper side of the air exit hole of the water tank where the main and auxiliary water tanks are connected. The bottom of the main water tank is connected to the cooling device through water pump. An INDEPENDENT CLAIM is included for water electrolyzer comprising outer shell, anode spliced mouth piece, cathode spliced mouth piece, sleeve body and bar body.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of the water fuel system.    Water electrolyzer (50)    Anode and cathode fixers (66, 84)    Electric source (71)    Water tank (80)    Cooling device (90)