The utility model provides a water-level alarm and control device, which comprises a water level sensor with electrodes[N0-N7], a sensor signal processing circuit, a water-level alarm and control circuit, and an alarm control actuator, wherein, the input end of the sensor signal processing circuit is connected to the gate circuit [I] for the water level electrode; the water-level alarm and control circuit has a time delay circuit [T], and the output end of the time delay circuit is connected to the power supply circuits of the siren [S] and the water pump[M]. The provided water-level alarm and control device of this utility model, utilizing the logicality of the gate circuit, after determining the level of a reference electrode, can determine the output end level of the gate circuit, and the output end of the gate circuit is connected to a water level electrode which connects with the reference electrode. Thereby, the purpose of samples on the output end of the gate circuit used as triggering signals for the switching circuit is realized. Utilization of the time delay circuit to make that the siren and the water pump are not activated immediately when the maximum water level is detected, and to start them after the confirm on real water lever within the delayed time.