The wall-flow diesel particulate filter is an efficient exhaust gas aftertreatment device that reduces particulate matter emissions. Exploring the gas-flow and particle deposition within the diesel particulate filter is essential for advancing regeneration technology and optimizing its structural design. In the present study, the commercial CFD code ANSYS FLUENT 15.0 is used to simulate the soot laden flow field, whereas the trapping and in-situ deposition of particles are implemented through user-defined-subroutines. The Euler-Lagrange method with user-defined functions is used to calculate particle concentration distribution in porous media. The effects of factors like inlet velocity, wall permeability, and particle size on particle deposition are systematically analyzed. Furthermore, the specific effects of these factors on the flow field characteristics within asymmetric channels are further explored. The study yields the following findings: an increase in the inlet velocity markedly elevates the flow velocity within the channels, leading to a significant change in hydrostatic pressure, and the resultant increase in static pressure difference between the inlet and outlet channels thereby induces a higher through-wall velocity. Higher wall permeability causes a more significant velocity rise in the inlet channel, thereby promoting increased particle depositionward the rear, with a maximum local deposition efficiency of 0.3 at a wall permeability of 1⋅ 10−10 m2. Enhanced inertia from larger particle sizes shifts the initial deposition point rearward, resulting in particles with a diameter of 2 μm beginning to deposit at 0.3 times the channel length from the inlet.