Rock core disking is one of the typical phenomena in high in-situ stress environment. The geometric characteristics and section shape of rock discing are related to the state of in-situ stress, and the site where this phenomenon occurs may not be suitable for in-situ stress measurement. Based on this phenomenon, the relationship between in-situ measurement data and in-situ stress of disked rock cores is established, and in-situ stress estimation is carried out to complement the in-situ stress measurement data. Based on the relevant hypotheses and theories at home and abroad, the physical and geometric characteristics of the disked rock cores are measured, and the stress state of the original rock is combined with the stress magnitude estimation formula based on the core discing. The in-situ stress of the 30~120m position of disked rock cores in Dandong, Liaoning Province was estimated. 73 representative disked rock cores were selected to estimate the in-situ stress magnitude of the section, and the measured data of hydraulic fracturing were supplemented. The supplemented in-situ stress data were more close to the reality. Compared with other estimation formulas based on core discing, the factors taken into account are more comprehensive, the measurement accuracy requirements are lower, and the calculation results are less biased and fluctuate. The results of calculation and comparison show that this method is suitable to be used as a supplementary source of in-situ stress data.