The invention provides a preparation method of a low-silicon low-chromium vanadium solution. The preparation method comprises the following steps: step 1, leaching vanadium-containing materials with water or acid solution, and carrying out filtering to obtain vanadium-containing leachate; step 2, heating the vanadium-containing leachate to 60-80 DEG C, adjusting the pH value to 7.0-9.0, adding sodium metaaluminate into the solution with the molar ratio of the sodium metaaluminate to the Si content in the vanadium-containing leachate being 0.5-1.0:1, and carrying out filtering to obtain low-silicon vanadium liquid; and step 3, adjusting the pH value of the low-silicon vanadium solution to 7.0-9.0, adding sodium sulfite with the molar ratio of the sodium sulfite to the Cr content in the vanadium-containing leachate being 0.4-1.0:1, and carrying out stirring and filtering to obtain the low-silicon low-chromium vanadium solution. According to the preparation method of the low-silicon low-chromium vanadium solution provided by the invention, silicon and chromium impurity elements in the vanadium-containing leachate are effectively removed on the premise of ensuring that the loss rate ofvanadium in the vanadium-containing leachate is as small as possible by controlling various process parameters, so that the quality of a subsequent vanadium product is ensured, the impurity removal efficiency is high, the process operation is simple and convenient, and the method has a wide application prospect.