How　to　tackle　the　difficulty　involved　in　optical　flow　calculation　caused　by　illumination　inconsistency　in　adjacent　video　frames　remains　an　open　challenge.　This　motivates　us　to　investigate　how　to　obtain　a　valid　and　accurate　optical　flow　field　which　is　robust　to　illumination　change　based　on　structure-texture　decomposition.　In　this　paper,　we　attempt　to　reveal　the　involved　technique　details　in　this　ROF　model　based　image　decomposition　and　carefully　examine　the　improvement　extent　quantitatively　by　experiment.　The　advent　of　structure-texture　decomposition　for　optical　flow　calculation　is　verified　by　experiment　results.　It　is　demonstrated　from　the　comparison　in　the　experiment　that　the　accuracy　of　optical　flow　field　estimated　by　TV-L-1　model　and　structure-texture　decomposition　based　method　outperforms　that　obtained　by　pure　TV-L-1　model　and　TV-L-1　and　filter　constancy　based　method.