The invention provides a multi-stage composite light source ultraviolet rapid curing device for a label printing machine. The multi-stage composite light source ultraviolet rapid curing device is composed of a rectangular box body, a light source controller, N ultraviolet powerful light source generators, a width detection mechanism and a speed sensor. According to the multi-stage composite light source ultraviolet rapid curing device for the label printing machine, ultraviolet light-emitting diodes and parabolic cylinder reflectors are adopted to form a multi-stage ultraviolet composite light source; ink on the surface layer and ink on the deep layer of label paper are cured at the same time; and in addition, the irradiation range and the irradiation intensity of two groups of light sources can be adjusted in real time by detecting the label printing width and the label printing speed in real time.