The invention discloses a compound using spirobibenzocycloheptene fluorene as a core, and applications in organic electroluminescent devices. According to the invention, the compound contains aspirobibenzocycloheptene fluorene structure, has strong rigidity, and further has characteristics of difficult crystallization and aggregation among molecules, good film-forming property and the like after the compound is linked to a carbazole derivative long branched chain structure or an arylamine derivative branched chain structure; due to different electron donating capacities of the branched chain groups, the HOMO energy levels of the material are different, and the compound can be used as different functional layer materials; the compound has high triplet state energy level, can effectively block energy loss, and is beneficial to energy transfer; and with the application of the compound as the organic electroluminescent functional layer material in the OLED device, the current efficiency, the power efficiency and the external quantum efficiency of the device are greatly improved while the service life of the device is obviously prolonged.