Normally-closed fireproof door state detection device

The invention discloses a normally-closed fireproof door state detection device which comprises a signal base arranged on the front face/back face of a door frame, at least one groove is formed in the signal base, and a signal transmitting module and a signal receiving module are correspondingly arranged on the two opposite inner side walls of the groove respectively. The signal blocking pieces are in one-to-one correspondence with the grooves, each signal blocking piece comprises a connecting base and a U-shaped bending part, the connecting bases are used for being arranged on the front face/back face of the door leaf, one ends of the U-shaped bending parts are perpendicularly connected with the connecting bases, and when the door leaf is closed, the U-shaped bending parts are arranged on the U-shaped bending parts. And the other end of the U-shaped bending part is inserted into the groove to block the signal transmitting module and the signal receiving module. 本发明公开了一种常闭式防火门状态检测装置，包括设置在门框正面/背面的信号座，所述信号座上设有至