The invention discloses a method for producing electron-grade thermal-resistant aluminum hydroxide. The method comprises the following steps: carrying out decontamination and purification on an aluminum hydroxide re-solution, adjusting solution molecules, and controlling decomposition speeds. Aluminum hydroxide micro powder produced by using the method is low in impurity content, the content of sodium oxide is up to 0.08%, the product granularity is 1-6mu m, reasonable granularity distribution is achieved, good crystal development is achieved, a clear crystal interface is achieved, and the crystal has a completely developed morphology, takes the shape of a similar sphere, has a high water loss temperature, and has a 1% water loss temperature up to 245 DEG C or greater.