The invention provides a rainwater grate with the waterlogging stopping function for an urban-underground-space entrance and exit part. The rainwater grate is composed of a base, a catchment groove, awater draining channel, a supporting column, a rainwater grate body, a flap valve hinge, a flap valve, a baffle, a balance weight, first water bag supports, containing grooves, containing holes, a second water bag support, an upturning gate, an upturning gate hinge, a rotating shaft, a water feeding pipe and a water discharging pipe. When rainfall is smaller than the urban-design flood control standard, and the road surface water level is lower than the urban-design flood level, the rainwater grate with the waterlogging stopping function for theurban-underground-space entrance and exit part is in the lying state; when rainfall is larger than the urban-design flood control standard, and the load surface water level is higher than the urban-design flood level, a water feeding pipe valve isopened to supply water to the water bag supports, and the rainwater grate with the waterlogging stopping function for theurban-underground-space entrance and exit part is uplifted and stands to stop urban waterlogging and guarantee the urban-underground-space safety. The rainwater grate is simple in structure, convenient to operate, good in water stopping effect and free of dismantling cost and isnot capable of consuming electric energy, and a small amount of water needs to be only consumed during starting and stopping every time.