The invention discloses a method for recovering sodium acid chromate from chrome-containing electroplating sludge. The electroplating sludge is blended with Na2CO3 according to a certain proportion and is baked at a certain temperature to obtain Na2CrO4, Cr<3+> is oxidized into Cr<6+> chrome and aluminum and zinc are taken as corresponding oxides; Cr, Al and Zn are dissolved in liquid by water soaking to generate respective salt, and the solid containing the metals such as Ni, Cu, Fe, Ca, Mg, and the like, is filtered and separated; the Na2CrO4 solution is transformed by hydrolysis acidification and Al2(OH)3 and Zn(OH)2 are removed to realize the separation of Zn, Al and Cr; the chrome-containing solution is acidated into sodium acid chromate (Na2Cr2O7), cooled after being concentrated to a certain volume, and filtered to remove sodium sulfate; the sodium acid chromate solution is processed by condensation, crystallization, centrifugation and drying to obtain sodium acid chromate finished product. By adopting sodium treatment and oxidation process, the rate of recovering chrome from chrome-containing electroplating sludge can exceed 90 %, and the resource utilization of electroplating sludge can be realized.