Inverted suspension mounting device for heavy bolts/nuts

The invention discloses an upside-down mounting device for heavy bolts/nuts, which comprises a base, a position adjusting mechanism, a fixing mechanism and a lifting rotating mechanism, and is characterized in that the position adjusting mechanism is connected with the base and is used for adjusting the position of the base; the fixing mechanism is used for being detachably connected with one end of a to-be-assembled bolt/nut. The bottom of the lifting rotating mechanism is connected with the base, the top of the lifting rotating mechanism is connected with the fixing mechanism, and the lifting rotating mechanism is used for driving a bolt/nut connected to the fixing mechanism to lift and/or rotate in the axial direction. The position of the whole device is adjusted through the position adjusting mechanism, so that the bolt/nut fixed to the fixing mechanism moves to the position under the to-be-installed position; the lifting and rotating mechanism can drive the bolt/nut connected to the fixing mechanism to a