The invention discloses a voltage detecting device, a detecting system and a detecting method compatible with multiple voltages. The detecting method comprises the steps of: connecting batteries of storage battery packs in different connecting manners according to different voltage types of the storage battery packs, and detecting voltage values of the batteries; when detecting the storage batterypack with 2 V single cells, adopting six voltage detecting interfaces for detecting 6 batteries which are 2 V single cells; when detecting the storage battery pack with 6 V single cells, connecting the six voltage detecting interfaces in series into two detecting interfaces, and then detecting 2 batteries which are 6 V single cells; and when detecting the storage battery pack with 12 V single cells, connecting the six voltage detecting interfaces in series into one detecting interface, and then detecting a battery which is a 12 V single cell. The detecting method adopts different connecting manners for connecting the voltage detecting device with the batteries of different types, realizes the compatible detection of various types of the storage battery packs, improves the detection efficiency and quality, reduces the detection cost, and can be widely applied to the technical field of storage battery monitoring.