The main objective of this paper was to investigate the pressure drop characteristics of ACT (asymmetric cell technology) design filter with various inlet mass flow rates, soot loads and ash loads by utilizing 1-D computational Fluid Dynamics (CFD) method. The model was established by AVL Boost code. Different ratios of inlet to outlet channel width inside the DPF (Diesel Particulate Filter) were investigated to determine the optimal structure in practical applications, as well as the effect of soot and ash interaction on pressure loss. The results proved that pressure drop sensitivity of different inlet/outlet channel width ratios increases with the increased inlet mass flow rate and soot load. The pressure drop increases with the increased channel width ratio at the same mass flow rate. When there is little soot deposits inside DPF, the pressure drop increases with the bigger inlet. As the filters accumulate soot, the pressure drop increases more slowly with the increase of the channel width ratio. Ash deposits on the inlet channel wall of DPF structure can prevent deep soot filtration and result in a smaller pressure drop as compared with no ash cases. All cases show that ACT design filters exhibit lower pressure drops with increased channel width ratios at high ash load (40 g/L) and soot load (6 g/L). In a word, the ACT design filter can improve soot and ash capacity, reduce the pressure drop at high soot and ash loads, and prolong DPF service lives.