To fabricate a stable surface with dynamic omniphobicity and self-cleaning function on inert substrates, in this paper, a facile approach was developed. The covalently-bonded dynamically-omniphobic surface (CBDOS) was prepared on inert stainless steel substrate by hydrosilylation, which was reacted between the Si-H bond in non-stoichiometry silicone rubber and monovinyl terminated polydimethylsiloxane. CBDOS was transparent, smooth, flouride-free and stable. Then, ATR-FTIR and XPS were used to characterize the chemical composition, which confirmed that liquid-like PDMS had been successfully covalently boned to CBDOS surface. AFM and FE-SEM were used to analyze the surface topography, and the results showed that CBDOS surface considerably smooth with nanoscale roughness. The AFM-derived root mean square roughness (Rq) of CBDOS surface was only 0.964 nm. Drop shape analyzer was used to study the anti-wettability and measure values of contact angle (CA), sliding angle (SA) and contact angle hysteresis (CAH). The water SA and CAH values were 2.20° and 1.75°, and n-hexadecane SA and CAH values were 7.33° and 7.34°, respectively. The data indicated that CBDOS revealed excellent dynamic omniphobicity and well storage stability. Therefore, CBDOS had outstanding self-cleaning function toward many kinds of common contaminants, whether they were polar or non-polar, soluble or insoluble, water-soluble or oil-soluble. It was believed that there were two key factors for CBDOS to realize excellent dynamic omniphobicity and self-cleaning function, one was the extremely homogeneous and smooth surface morphology, the other was the high mobility and flexibility of liquid-like PDMS which was only one end covalently grafted to CBDOS surface. This approach had lots of advantages such as simple operation, mild conditions and non-pollution, in addition, it could be applied to all types of substrates. Furthermore, due to the strategy of covalently bonding, the stability of dynamically omniphobic surfaces based on liquid-like PDMS had been improved distinctly.