The invention discloses an automatic interval adjusting device and an automatic interval adjusting method. The automatic interval adjusting device comprises a supporting part, a moving part and an adjusting part, the supporting part comprises a support and a fixing arm connected to the support, the moving part comprises guide rods, multiple moving blocks and multiple transmission rods, the guide rods are fixed on the support, the moving blocks are slidably connected to the guide rods and used for being connected with equipment needing interval adjustment, each transmission rod is hinged on the corresponding moving block, the transmission rods are positioned in a same plane, and adjacent transmission rods are hinged. The adjusting part comprises an adjusting screw, a shaft sleeve and a driving part, the driving part is fixed on the fixing arm, connected to the adjusting screw and used for driving the adjusting screw to rotate, the adjusting screw is parallel to the guide rod, and the shaft sleeve sleeves the adjusting screw, is in threaded connection with the adjusting screw and is fixed to one of the moving blocks. The automatic interval adjusting device can realize multi-unit synchronous adjustment and is accurate in interval adjustment.