The utility model relates to the field of the automobile maintenance and detection equipment, in particular to an automatic gearbox detection device of an automobile. The automatic gearbox detection device comprises a rack, a loading assembly and a power drive assembly, wherein the loading assembly and the power drive assembly are fixed on the rack. The automatic gearbox detection device is characterized in that the automatic gearbox detection device is provided with a telescopic spindle and a self-adjustable center bushing device, the spindle and a gearbox drive shaft are connected through a spline, the spindle is provided with a gearbox drive shaft fastening rack, and the gearbox drive shaft fastening rack is provided with fastening screws for fastening the gearbox drive shaft. According to the automatic gearbox detection device, the installation of the gearbox is more convenient, the center bushing installation device of the power drive assembly is an interval-adjustable structure, and the spindle is provided with an axial movement spacing device. The above design enables the operation of the device to be more convenient.