Atmospheric dielectric barrier discharge (DBD) is a promising approach for large‐area deposition, whose spatiotemporal evolution determines the deposition rate and film chemistry. To investigate the relationship between the discharge and deposition behavior of tetraethoxysilane/oxygen/argon (TEOS//Ar) DBD, a one‐dimensional (1D) fluid model was constructed and experimentally verified. The calculation results reveal that TEOS mainly affects the discharge behavior via Penning ionization, while mainly affects discharge via attachment reaction. Penning ionization reduces the excited Ar and the attachment reaction reduces the number of discharges in half voltage cycles. As a result, merely increasing the concentration of TEOS or may not proportionally increase the deposition rate of relevant reactive species.