Roof separation instrument capable of setting initial separation value

The utility model relates to a roof bed separation instrument capable of setting a bed separation initial value, which is characterized in that a guide pipe and a tray are designed into a split structure, an adjusting external thread is additionally arranged at the bottom of the guide pipe, an adjusting nut and an adjusting cushion block are additionally arranged on the external thread, and when the bed separation instrument is mounted, after deep and shallow base point anchor flukes are mounted in place, the guide pipe of the bed separation instrument is inserted into a drill hole; the tray abuts against the direct top lower edge, then thin steel ropes at the deep base point and thin steel ropes at the shallow base point are tensioned respectively, and the thin steel ropes are connected with the sliding blocks by fastening screws on the sliding blocks connected with the thin steel ropes respectively. The screw wrench is rotated, the adjusting nut moves upwards, the adjusting cushion block and the tray are pu