Automatic door locking device

The utility model relates to an automatic door locking device. The automatic door locking device is characterized in that an adjusting frame is arranged in a space formed between an upper lock cylinder cover and a lower lock cylinder cover and is in slide fit with slide guide rails on the lower lock cylinder cover, an adjusting guide rail is arranged on the adjusting frame, a locking block is arranged beside the adjusting guide rail, the height of the locking block can be adjusted by the adjusting guide rail, and the locking block can be driven by the adjusting guide rail to move up and down, so that a spring bolt can be unlocked or locked. According to the technical scheme, the automatic door locking device has the advantages that when locking signals are generated by a main control board, an electromagnetic coil is energized by positive direct currents, permanent magnets are pushed to move, accordingly, the adjusting frame is driven to move, the adjusting guide rail runs to a low-potential position, the loc