The invention discloses a colorless highly-transparent polyimide film as well as a preparation method and an application thereof. The film is prepared from semi-aromatic polyimide resin of which the structural formula is shown as formula I, wherein Al is an alicyclic structure, R1 is an aromatic diamine structure containing fluorine and sulfone, R2 is another aromatic diamine structure, and n:m=(0-400):1. The film has excellent optical transparency, colorless transparency of the film with great thickness (greater than or equal to 100 mu m) can be realized, the initial light-transmitting wavelength is below 300nm, and the light transmittance in a visible region is greater than or equal to 90%; and meanwhile, the film shows excellent heat resistance and mechanical property, and has important application values in the manufacturing of the photoelectric devices such as a solar battery, a display, an electronic book, an electronic label, a photoelectric sensor and the like.