The invention discloses a hyperbranched white light conjugated polymer and a preparation method and application thereof. In the polymer, a red phosphorescence Ir (III) complex is taken as a core, and a polyfluorene derivative blue-fluorescence material is taken as a skeleton. The skeleton contains or does not contain carbazole derivatives. By controlling the content of the red phosphorescence Ir (III) complex, the white light emission of the hyperbranched white light conjugated polymer is realized through complementation of the blue color and the red color. An electroluminescence spectrum of the conjugated polymer covers the whole visible light emission area, and approaches pure white light emission. The hyperbranched white light conjugated polymer can be used as a luminescent layer materials to prepare organic light-emitting devices.