The invention discloses a 2,5,8,11-tetrabromo-1,6,7,12-tetrachloro 3,4:9,10-tetracarboxylic acid perylene diimide compound, a preparation method and an application thereof. The compound is as shown in a formula I and a formula I'. The compound as shown in the formula I and the formula I' has a yield of 30-95 % after separation and purification, and is confirmed to have a correct structure through an NMR spectra (1H-NMR) and a mass spectrometry (MS). The method is simple and high-efficient, greatly reduces reaction steps, prevents use of expensive heavy metals, and saves cost, solvents and time.