A buckle device capable of displaying a locked state, comprising: a main body unit comprising a main body defining and surrounding an accommodating space; a latch unit comprising a tongue element detachably arranged in the accommodating space; a fastening unit comprising at least one bolt body arranged on the main body, wherein the at least one bolt body detachably interferes with the tongue element arranged in the accommodating space, when the at least one bolt body interferes with the tongue element, the tongue element is securely fastened to prevent the tongue element from leaving the accommodating space; an electromagnetic unit comprising at least one electromagnetic module and at least one electromagnetic rod, the at least one electromagnetic module being arranged in the main body, the at least one electromagnetic rod being arranged through the at least one electromagnetic module; and a control unit comprising a control module electrically connected to the at least one electromagnetic module, a magnetic bolt detection module arranged on the main body and electrically connected to the control module, and a display module electrically connected to the control module; wherein the control module controls whether the electromagnetic module is excited or not, the magnetic bolt detection module is configured to detect the position of the at least one electromagnetic rod; wherein when the electromagnetic module is excited and generates a magnetic force for the at least one electromagnetic rod, the at least one electromagnetic rod is moved to a release position, such that the at least one electromagnetic rod and the at least one bolt body are separated from each other; wherein when the electromagnetic module is not excited and the at least one bolt body locks the tongue element, the at least one electromagnetic rod is moved to a lock position and interferes with the at least one bolt body, in order to lock the at least one bolt body to prevent the at least one bolt body from releasing the tongue element, and the control module is configured to receive detection information of the magnetic bolt detection module and controls the display module to display a current state according to the position of the at least one electromagnetic rod, characterized in that the latch unit further comprises a belt connected to the tongue element, and a roll module connected to the belt and electrically connected to the control module, the roll module is configured to rewind the belt. a main body unit comprising a main body defining and surrounding an accommodating space; a latch unit comprising a tongue element detachably arranged in the accommodating space; a fastening unit comprising at least one bolt body arranged on the main body, wherein the at least one bolt body detachably interferes with the tongue element arranged in the accommodating space, when the at least one bolt body interferes with the tongue element, the tongue element is securely fastened to prevent the tongue element from leaving the accommodating space; an electromagnetic unit comprising at least one electromagnetic module and at least one electromagnetic rod, the at least one electromagnetic module being arranged in the main body, the at least one electromagnetic rod being arranged through the at least one electromagnetic module; and a control unit comprising a control module electrically connected to the at least one electromagnetic module, a magnetic bolt detection module arranged on the main body and electrically connected to the control module, and a display module electrically connected to the control module; wherein the control module controls whether the electromagnetic module is excited or not, the magnetic bolt detection module is configured to detect the position of the at least one electromagnetic rod; wherein when the electromagnetic module is excited and generates a magnetic force for the at least one electromagnetic rod, the at least one electromagnetic rod is moved to a release position, such that the at least one electromagnetic rod and the at least one bolt body are separated from each other; wherein when the electromagnetic module is not excited and the at least one bolt body locks the tongue element, the at least one electromagnetic rod is moved to a lock position and interferes with the at least one bolt body, in order to lock the at least one bolt body to prevent the at least one bolt body from releasing the tongue element, and the control module is configured to receive detection information of the magnetic bolt detection module and controls the display module to display a current state according to the position of the at least one electromagnetic rod, characterized in that