Robinia pseudoacacia L. is a tree widely dispersed in France that is characterized by good growth rates and important biomass production, which produces wood with very high natural durability used for outdoor fence posts, timber, and barrels to age vinegars and wines. Its mature heartwood presents high resistance against wood fungi decay and contains two main flavonoid extractives, dihydrorobinetin—the most abundant—and robinetin that present interesting biological activities. The aim of the present study was to optimize a procedure allowing an important recovery of purified dihydrorobinetin from R. pseudoacacia wood, representing an interesting sustainable, local, highly available, and, consequently, economical source of bioactive components. The extraction of dihydrorobinetin was first optimized by evaluating the influence of various extraction parameters such as temperature, extraction time, solvent nature, and wood/solvent mass ratio to obtain an efficient, safe, and low cost extraction. Then, dihydrorobinetin was purified over 95% using centrifugal partition chromatography (CPC). CPC purification was first developed on a small volume column with low amounts of injected extract, then scaled-up on a 200 mL column with higher sample loading capacity in order to purify more than 1.3 g of dihydrorobinetin in one run.