Abstract: A new type of multi-field collaborative processing technology that couples phase change aggregation and turbulent aggregation has been proposed to address the problem of low efficiency in the treatment of sintering flue gas ultrafine dust. By using numerical simulation methods, the aggregation behavior of sintering ultrafine dust under multi-field effects and the influence of its evolution parameters on aggregation efficiency were thoroughly investigated. The research results show that a lower inlet velocity can significantly improve the aggregation efficiency, as evidenced by a decrease in the average particle size of sintering ultrafine dust and an increase in the number density of large particle dust at the outlet. When the inlet velocity is 2 m·s^-1, the average particle size is 16.1 μm, and the number density of large particle dust at the outlet is 5.08 × 10⁴ particles·cm^-3. Although an increase in initial volume fraction is not conducive to dust growth, it is directly proportional to the number density of large particle dust at the outlet. When the volume fraction is 0.0023, the average particle size is the largest, at 19.8 μm, and when the volume fraction is 0.0062, the number density of large particle dust is the highest, reaching 7.4×10⁴ particles·cm^-3. This indicates that a higher volume fraction is beneficial for dust treatment. An increase in the initial particle size of the dust will lead to a decrease in its final particle size density, which is inversely proportional to the number density of large particle dust at the outlet. When the initial particle size is 0.78, the final particle size is the smallest, at 38.9 μm, but the outlet density is the highest, at 8.17×10⁴ particles·cm^-3. This indicates that a smaller initial particle size is more conducive to the effectiveness of the collaborative processing technology.