As an important oil recovery region in China, Xinjiang Oilfield has witnessed an expanded heavy oil production scale year by year. The reinjection treatment of wastewater from heavy oil production poses adverse environmental impacts, making the proper handling and reuse of this wastewater an unavoidable issue for the green and sustainable development of oilfields. Reusing the wastewater in steam injection boilers is a feasible and effective solution. However, salt deposition in boiler tubes, where wastewater serves as the primary feedwater, is a significant problem. Thus, this study investigated the mechanism of salt deposition by analyzing the microscopic morphology and elemental composition of salt scale samples. The results reveal that under high temperature and pressure, carbonates and bicarbonates induce salt scale growth, with the primary component being Na₂Si₂O₅. Addressing practical challenges such as the inefficacy of treatment measures for salt deposition in boiler tubes, the research uncovers the intrinsic mechanisms of salt deposition and explores effective treatment methods. Then, a self-system flushing solution during boiler operation is proposed. Experimental results demonstrate that this solution achieves excellent descaling effects under specific conditions, restoring 70% to 95% of the pressure loss caused by salt deposition without generating solid or liquid wastes. This approach provides an effective pathway for resolving salt deposition in steam injection boilers by reusing heavy oil thermal recovery wastewater.