The invention discloses a three-dimensional cross-hole resistivity tomography method based on a network parallel electrical method. Firstly hole drilling is performed and then an electrode measuring line is arranged; then three-electrode apparent resistivity acquisition is performed on the electrodes on the measuring line for multiple times by using the network parallel electrical method and thendifferent positions of the three electrodes are classified. The calculation method of the three-dimensional space position of the corresponding apparent resistivity is determined according to different types of three-electrode space positions and then the three-dimensional space positions of different types of apparent resistivity are obtained. Finally, the apparent resistivity distribution map ofthe three-dimensional space volume surrounded by multiple drill holes is generated, and the space distribution characteristics of underground anomalies can be reflected according to the distributionmap and data support can be provided for the subsequent underground space development.