The invention discloses a collecting device for researching soil microbial diversity. The collecting device comprises a box and trays, wherein a bottom plate is fixedly connected to the bottom end ofeach tray, layer supports are fixedly connected to one sides of the first tray, the second tray and the third tray, a handle is fixedly connected to one end of each layer support, one end of the firsttray is fixedly connected with a warming bottom plate, the bottom of the third tray is fixedly connected with a normal temperature bottom plate, sliders are arranged at one ends of a cooling bottom plate, the warming bottom plate and the normal temperature bottom plate, partition plates are arranged at the upper ends of the first tray, the second tray and the third tray, and attaching blocks areuniformly mounted on the partition plates. For the collecting device provided by the invention, the plurality of layers of trays are added, so that soil of various types can be collected at one time for research, the work efficiency is improved, the warming bottom plate, the cooling bottom plate and the normal temperature bottom plate are added, so that the research is relatively accurate, the attaching blocks and label paper are added, so that the work efficiency and research accuracy are indirectly improved.