Ultraviolet lamp

An ultraviolet lamp, comprising a lamp tube and an electrode, a discharge cavity being formed in the lamp tube, wherein a thermistor is disposed on an end socket at a first end of the lamp tube, a receiving groove communicated with the discharge cavity is formed in the end socket, amalgam is stored in the receiving groove, and the thermistor heats the amalgam in the receiving groove in the end socket, further comprising an outer sleeve disposed around the lamp tube and spaced from the lamp tube, wherein a distance between an inner wall of the outer sleeve and an outer wall of the lamp tube is 1.0 mm-5.0 mm, the lamp tube and the outer sleeve are connected in a sealed manner, at least one of an inert gas and nitrogen is filled between the lamp tube and the outer sleeve, both the lamp tube and the outer sleeve are made of quartz pervious to 185 nm and 253.7 nm ultraviolet light, and the lamp tube and the outer sleeve are integrated and are able to output the 185 nm and 253.7 nm ultraviolet light, wherein at least one terminal of a thermistor lead wire is connected to one terminal of electrode lead wires, wherein the Curie temperature of the thermistor ranges from to [T1+(T2−T1)/5] to [T1+4*(T2−T1)/5], wherein T1 and T2 are respectively a minimum operating temperature and a maximum operating temperature of the amalgam in a continuous region where the ultraviolet radiation power is from 90% to 100% when, the input power of the ultraviolet lamp is 100%, wherein the amalgam comprises bismuth, indium, tin and mercury, and the proportion of the mercury is 2.0%-2.5%.