A soil turning device comprises a cutterhead shaft. Cutterheads in linkage with the cutterhead shaft are mounted on the cutterhead shaft. One or more moisture scavenger auxiliary pipes are arranged onthe cutterhead shaft in the axial direction. A plurality of moisture scavenger spraying holes are formed in each moisture scavenger auxiliary pipe towards the outer side. The cutterheads comprise three first cutterheads, second cutterheads and two third cutterheads. One of the cutterheads is arranged at the center of the cutterhead shaft, and the other two cutterheads are symmetrically arranged on the outermost side of the cutterhead shaft. The two third cutterheads are symmetrically arranged between the adjacent first cutterheads with the center of the cutterhead shaft as the symmetric axis.The second cutterheads are arranged between the first cutterheads and the third cutterheads. The diameters of the first cutterheads and the diameters of the second cutterheads are both smaller than the diameters of the third cutterheads. According to the soil turning device, the obvious relieving effect is achieved on the problems that large-block soil is not easy to turn, and the turning treatment efficiency of polluted soil with the high water content is low.