Diesel particulate filter is one of the most effective and direct methods to filter diesel particulate matter. Many factors affecting the efficiency and pressure of diesel particulate trap are studied in this paper. Based on AVL-BOOST software, the simulation model of DPF is established. Based on the calculation of multi plans which control the different parameters such as geometry, temperature, porosity and other factors of the diesel particulate filter, the effect of these parameters on efficiency and pressure of diesel particulate filter is studied, to understand the influence relations between different parameters. The models of pressure drop are introduced. The effects of monolith length, monolith volume, mass flux, boundary and initial temperature on pressure drop are analysed. Results show that the structure of DPF has little impact on pressure drop; DPF regeneration does not change the effects of monolith length, monolith volume, loaded soot mass on pressure drop; When the temperature is 773 K, the mass flux has an important influence on pressure drop; The soot consumption rate is no longer changing when the temperature reaches 873 K; The coupling of temperature and parameters affects the pressure drop. The importance of filter structural parameter to calculate the pressure drop and filtering efficiency is further analysed. The results further improve the theoretical analysis of DPF efficiency characteristics, DPF regeneration time and subsequent experiments.