Municipal engineering foundation pit safety protection device

The invention relates to the technical field of foundation pit protection, and discloses a municipal engineering foundation pit safety protection device which comprises supporting mechanisms which are vertically arranged and used for providing supporting force and protection mechanisms which are horizontally arranged and used for providing interception force, and a plurality of protection mechanisms are vertically arranged between the two supporting mechanisms. The supporting mechanism comprises a supporting box body and supporting square boxes arranged on the two opposite side walls of the supporting box body in a penetrating mode, the multiple sets of supporting square boxes are arranged in the vertical direction, the supporting square boxes are provided with ball through grooves penetrating through the top faces of the supporting square boxes, and the protection mechanism comprises a horizontally-arranged steel wire stranded wire and protection balls fixed to the two ends of the steel wire stranded wire; t