Abstract: To address the asymmetric large deformation of a gateroad in a fault-affected isolated working face subjected to the superposition of residual abutment pressure from an adjacent gob, advance mining-induced stress, and fault-related tectonic stress, the transport roadway of the 2-621 working face in Liyazhuang Coal Mine was selected as the engineering background. Field monitoring, complex-variable analytical modelling, FLAC^3D numerical simulation, grouting-modification tests on coal containing structural weak planes, and an industrial field trial were combined to investigate the asymmetric deformation mechanism of the near-fault isolated coal roadway and develop an external anchorage–internal destressing control method. The results show that the fault weak plane disrupts the continuity of the coal–rock mass and alters the load-transfer path, resulting in higher deviatoric-stress concentration and more severe deformation on the fault side than on the solid-coal side. Under the original support condition, the rib deformations on the fault side and solid-coal side were approximately 780 and 460 mm, respectively. Analytical results from the spatial twin-opening model of the roadway and destressing cavities indicate that excessively small cavity spacing causes stress-field overlap, whereas excessively large spacing weakens the destressing effect. A spacing of 7 m was therefore identified as suitable for the investigated conditions. Combined with the numerical results, a zoned differential destressing scheme was developed: the fault side was avoided within the 10 m near-fault intensive-control zone; the cavity position was advanced and the cavity length reduced within the 20 m structural-transition zone; and the parameters gradually approached the conventional design within the 30 m zone farther from the fault. The grouting-modification tests showed that the structural weak plane reduced the peak strength of the coal to approximately 5.5 MPa. After grouting, the peak load-bearing capacity increased to approximately 13.5 MPa, and the failure mode changed from weak-plane-controlled sliding to coordinated deformation of the composite specimen. Following field implementation, the surrounding-rock deformation remained continuous and controllable. These results demonstrate that the external anchorage–internal destressing method, which combines shallow anchorage and grouting to reconstruct the load-bearing structure with deep cavity destressing to redistribute high deviatoric stress, can effectively control asymmetric large deformation in near-fault isolated coal roadways.