Carbonate rock fractures and caves are well-developed and highly heterogeneous. The pore size and porosity of these fractures and caves determine to some extent the oil and gas storage capacity of the reservoir. The higher the pore size and porosity, the better the reservoir's storage and permeability capabilities. Electrical imaging plays an indispensable role in the effectiveness evaluation of carbonate reservoirs due to its high resolution and high coverage. In order to more accurately evaluate the effectiveness of reservoirs, the idea of using core scale electrical imaging images is proposed. Firstly, the electrical imaging images are preprocessed and fracture hole extraction is carried out through techniques such as Filtersim, grayscale reconstruction transformation, watershed algorithm, and morphological algorithm. Then, the core fracture holes are marked using tools such as Photoshop, and the fracture hole parameters of the two are calculated separately. Different models are used to fit the relationship between the electrical imaging and the rock core fracture hole parameters. Finally, different relationship equations are applied to actual well data. The results indicate that the scale model fitted by a quadratic function can better reflect the complex relationship between the fracture and cavity parameters in electrical imaging and the true fracture and cavity parameters in the rock core. Moreover, the absolute error of the extracted fracture and cavity parameters from electrical imaging corrected by this model is controlled within 3.5%. The accurate extraction and correction of fracture parameters can provide a more accurate data basis for the effectiveness evaluation of reservoirs.