Underwater lamp alarm

The utility model relates to an underwater lamp alarm which includes a transformer and an alarm processor. The transformer, a power supply, a capacitor and an underwater lamp form a circuit. An alarm circuit is arranged in the alarm processor. A firs signal input terminal, a second signal input terminal, a third signal input terminal, a fourth signal input terminal, and a fifth signal input terminal, which are connected with the alarm circuit, are arranged on the alarm processor so as to detect voltage signals at the two ends of the power supply, the capacitor and the underwater lamp. A short-circuit signal output terminal, a public output terminal and an open-circuit signal output terminal, which are connected with the alarm circuit, are arranged on the alarm processor so as to realize fault alarm of the underwater lamp. The underwater lamp alarm is capable of timely providing fault alarm and classifying fault types.