The temporary plugging and fracturing (TPF) technique is an effective method for refracturing low-productive wells and obtaining complex fractures by fracturing in deep coal seams. In this work, the applicability of TPF technique and the growth law of diverting hydraulic fractures (HF) in high stress levels (HSL) were analyzed by numerical simulation, and feasible reservoir construction recommendations were proposed. To simulate the entire TPF process, a composite progressive modeling concept was introduced. The results indicated that the presence of coal cleats facilitated HF growth, particularly under low stress difference (LSD) and low stress level (LSL) conditions. During the TPF process, the initial diverting distance of HF increased from 2.26 m to 3.22 m as the stress difference (ΔS) decreased from 12 MPa to 2 MPa under HSL conditions. Additionally, the tortuosity of the HF increased from 24.67% to 65.94%, while deviation angle remained constant. Under LSL conditions, these three parameters showed a negatively correlation with ΔS (6 MPa–2 MPa), and their sensitivity to ΔS was greater than that observed under HSL conditions. Overall, the effectiveness of the TPF technique was weaker in deep seams compared to shallow ones. In deep seams with HSL conditions, a high stress difference (HSD) contributed to HF growth but lacked sufficient diverting ability, whereas the LSD condition showed the opposite trend. To enhance the effectiveness of the TPF technique, engineering measures such as higher liquid injection rate were necessary. Increasing the injection rate from 0.001 m3/s to 0.005 m3/s (ΔS = 10 MPa) improved the diverting deflection angle from 0° to 10.25° and the tortuosity from 30.62% to 35.48%. These improvements were more significant in LSD (ΔS = 6 MPa and 2 MPa), resulting in a ∼90 reduction in fracturing duration. The high-pressure fluid provided strong impetus for HF growth, and its alteration of the local stress field enhanced the induction of weak surface, thereby prompting the formation of complex fractures.