The invention relates to the technical field of soil nutrient research, in particular to a soil nutrient in-suit culture and sampling device which comprises a guide tube and a tubular film. The tube wall of the guide tube is of a bilayer structure, the tubular film is clamped between the two layers of the tube wall of the guide tube, the lower end of the tubular film extends out from the lower end of the guide tube, and barbs are arranged on the film surfaces of the inner side and/or the outer side of the extending-out section of the tubular film. When the guide tube is inserted into soil, the extending-out section of the tubular film turns over to the inner layer or outer layer of the tubular wall of the guide tube; when the guide tube is drawn out from soil, the barbs on the extending-out section of the tubular film can hook soil to enable the tubular film to stay in soil. Soil samples can be enabled to be separated from other soil in situ, then culture study is performed, the surrounding soil cannot be destroyed in the whole process, protection of the natural environment is benefitted, and soil sampling efficiency can be increased greatly.