As an important means of pretreatment of iron ore concentrate，high-pressure roller mill technology can significantly improve the physical and chemical properties of iron ore particles，and enhance the pelletizing performance and roasting consolidation behavior of pellets. In this paper，the effects of high-pressure roller mill pretreatment on the properties of fresh pellets and the strength of roasted pellets are systematically investigated using mixed iron concentrate from a domestic iron and steel enterprise， and the mechanism of strengthening consolidation is revealed. The results show that the proportion of fine particle size (＜0.074 mm， the mass fraction of particle size is increased from 83.70% to 91.77%) and the specific surface area (from 2 424. 07 cm²/g to 3 331. 60 cm²/g) of iron concentrate by mechanical activation， and enhance the adhesion capacity between particles. Proper high-pressure roller mill pretreatment (2 times) can effectively improve the strength of the fresh pellet，but excessive roller mill (4 times) will reduce the plasticity of the fresh pellet and reduce the compressive strength due to the fineness of the particles. In addition， the appropriate roller mill feeding moisture (8%) and bentonite dosage (1.2%) can further optimize the fresh pellet performance. During the roasting process， the high-pressure roller mill pretreatment can reduce the activation energy of the solid-phase reaction， so that the pellets can be consolidated efficiently at a lower temperature. The compressive strength of the pellets prepared by two roller mills can reach 2 599 N/P when roasted at 1 110 ℃，which meets the production requirements. The untreated group needs 1 200 ℃ (strength 3 496 N/P) to meet the production strength requirements. However，excessive roasting temperatures (＞1 200 ℃) can weaken the bridge connections due to the formation of excessive low melting point liquid phases， resulting in a decrease in pellet strength. The high-pressure roller mill pretreatment realizes the low-temperature and efficient consolidation of pellets ( the roasting temperature is reduced by 90～100 ℃) through mechanical activation and particle surface modification，which can provide theoretical basis and technical support for energy conservation and emission reduction in the steel industry.