The invention relates to a suspending device of a suspended ceiling. The suspending device comprises a clamp piece, an adjusting rod and a suspender. The clamp piece is provided with a clamping groove. A connecting portion is arranged on the side face of the clamping groove. One end of the adjusting rod is connected with the connecting portion. The adjusting rod can move and adjust relative to the connecting portion. A spherical shell hoop is arranged at the other end of the adjusting rod. The suspender is provided with a ball cap. The ball cap can be clamped into the spherical shell hoop. One end of the suspender is connected with a suspended ceiling unit body. The suspending device of the suspended ceiling is convenient to fix, install, detach and maintain, and the construction period is effectively shortened; in addition, transverse, vertical and angular fine adjustment of the suspended ceiling unit body can be achieved in the installation process, and the installation precision and convenience are improved.