Provided is a double-filament X-ray tube. An X-ray tube shell is equipped with a cooling device. In the X-ray tube shell, a 1# filament and a 2# filament are arranged at the position of the ray tube cathode, and a double-target-surface anode target is arranged at the position of the ray tube anode. The X-ray tube shell, at the position corresponding to the head of the double-target-surface anode target, is provided with a 1# ray emission window and a 2# ray emission window. A high-voltage cable is inserted in the power input end in the ray tube shell. The double-filament and symmetric-target-surface structure prolongs the service life of the X-ray tube; a single-filament working mode is adopted and the window for working is selected according to needs, which can avoid trouble brought by ray tube rotation; and the filaments can work alternately, symmetric double-position detection is realized, the rest-work time ratio is prolonged, the heat radiation time of the anode target is prolonged, and the working performance of the ray tube is maintained.