Basis weight uniformity of melt-blown fibrous webs is attracting considerable interest because it directly affects the application performance of nonwovens. There are numerous studies which introduce factors of processing conditions on the basis weight uniformity based on their final applications. However, theoretical research is still scarce. This paper describes the numerical modeling (bead-viscoelastic element fibrous model) involving fibrous web structure generation and basis weight uniformity evaluation. The effects of four processing conditions, including velocity of air jet and suction, die-to-collector distance, and moving speed of collector, on the basis weight uniformity of the fibrous web were quantitatively analyzed. Additionally, computational fluid dynamics simulation was employed to study the air flow (including the suction) in the melt-blowing process. The simulated results were in good agreement with the experimental data. The numerical model was practical and could better be used to research the problems on fibrous web formation and structures.