The invention relates to the technical field of underground garages, in particular to a safety protection device of an underground garage. The safety protection device includes a first box, a water
fender mechanism, a
backup storage battery, a sealing mechanism, a manipulation mechanism, a first guide rail bracket, a lifting mechanism, a bottom plate, a top plate and a second guide rail bracket. According to the safety protection device of the underground garage, the water
fender mechanism for water prevention is placed underground an entrance of the underground garage, when the dangerous situation of flood occurs,
ponding can be effectively blocked simply by driving the lifting mechanism and the water
fender mechanism to move and making a water fender flexible plate lifted along the guiderail brackets, no manual operation is needed, a water fender
system is laid rapidly, the dangerous situation can be dealt with in time, the lifting height of the water fender flexible plate can be adjusted freely, and the safety protection device can be in use at
ponding states of different degrees; a propulsion mechanism can be driven to rotate, therefore, an
extrusion plate, the water fender flexible plate and the inner wall of a flow groove are tightly attached, the sealing effect is improved, and infiltration of water is avoided; through a reinforcement rod, the water fender flexible plate is supported, and the strength of the water fender flexible plate is improved.