The magnitude and direction of in- situ stress are important parameters in the deployment of injection production well pattern, the design of hydraulic fracturing simulation, and the evaluation of induced earthquakes. The Anelastic Strain Recovery (ASR) in- situ stress measurement method was employed to obtain the in- situ stress state in 3~4 km depth of dry hot rock in the Matouying area, Laoting County, Tangshan City. The results show that: ① the magnitude of in- situ stress increases with depth within a range of 3139~3934 m depth, the minimum horizontal principal stress is 59.0~90.7 MPa, the maximum horizontal principal stress is 103.7~123.6 MPa, and the maximum horizontal principal stress direction is N83~114°E. ② The relationship of three principal stresses is σH＞σv＞σh, which indicates that the tectonic stress field gives priority to the horizontal stress, and the stress state is favorable for activity of strike- slip faults. ③ The result of stability of the fault studied according to Mohr- Coulomb criterion, shows that the ratios of shear to effective normal stress are lower than those from Byerlees law, indicating that the faults are in the relatively stable stress environment near the well M1 in Matouying area within a depth of 3~4 km. ④ The analysis of the relationship between the water injection and fault stability shows that the faults may become unstable near the injecting well, when the continuous injection pressure on the ground reaches or exceeds about 28 MPa during the water injection at 3900~4000 m depth in the study area, leading to the occurrence of medium and small earthquakes, which should be prevented in the development and utilization of the dry hot rock. This study has certain reference value for the analysis of geodynamics and the development and utilization of dry and hot rocks in Tangshan area.