The invention belongs to the technical field of polymer materials, and concretely relates to a functionalized organosilicon compound containing benzocyclobutene, and a preparation method thereof. The functionalized organosilicon compound containing the benzocyclobutene is prepared through reacting an organosilicone precursor containing the benzocyclobutene and a substrate containing hydroxyl under an alkaline condition, and can be subjected to reduced pressure distillation or column chromatography purification. The functionalized organosilicon compound containing the benzocyclobutene can be used for polymerization reaction, and can be pre-polymerized in a sym-trimethylbenzene solvent at the temperature of 150 to 180 DEG C to obtain a prepolymer with a certain molecular weight, and a thin film is prepared through further spin-coating and post curing; a nitrine type photosensitizer can be added in a monomer prepolymer containing double bonds so as to be used for preparing a photoresist, which can be applied in the fields of electronic packaging and integrated circuits.