The invention provides a novel burglar alarm for a mobile phone store. The novel burglar alarm comprises an external power interface, a voltage stabilizing circuit, a single-chip microcomputer, a detecting circuit, an alarming circuit and a super capacitor. The external power interface is connected with the alarming circuit and the voltage stabilizing circuit which supplies power for the single-chip microcomputer. The detecting circuit detects the connection condition of an external sample mobile phone and provides external sample mobile phone connection condition information for the single-chip microcomputer. The single-chip microcomputer controls the alarming circuit to give out an alarm after receiving the external sample mobile phone connection information. The super capacitor is powered by the voltage stabilizing circuit and supply backup power to the single-chip microcomputer. The novel burglar alarm has the advantages that the burglar alarm is simple in structure and convenient to use; the super capacitor is small in size, long in service life, wide in application environment, capable of being charged and discharged for unlimited times, free of leakage and explosion during use, and capable of allowing the burglar alarm to give out an alarm for about one minute after mains supply is cut off so as to remind a shop assistant to treat problems; due to the fact that the super charger is small in size, the size of the burglar alarm is reduced correspondingly; cost is saved, and convenience in maintenance is achieved.