Disclosed is system and method for emergency supervision of stormwater inlets in a smart city based on an IoT large model. The method includes determining blocked stormwater inlet and unblocked stormwater inlet based on real-time water accumulation data of the stormwater inlets; acquiring a water accumulation data sequence of the blocked stormwater inlet, and determining a water accumulation growth feature of the blocked stormwater inlet; determining a first cleaning point and its first priority level; determining a blockage probability distribution of the unblocked stormwater inlet; and determining a second cleaning point based on the blockage probability distribution; and generating a cleaning instruction including a cleaning path and a cleaning sequence based on the first cleaning point, the first priority level, and the second cleaning point, and controlling an autonomous cleaning machine to move along the cleaning path and to perform cleaning on corresponding stormwater inlets based on the cleaning sequence.