A lot of experiments about the anodization of A0 pure aluminum in oxalic acid solution were carried out. The technology parameters were decided, including the anode current density, the oxidization time and the temperature of the electrolyte solution. During the anode oxidization of the pool shell, some special key technologies were solved, including the oxidization technology of large equipment, the technology of the treatment with layer by layer and sealing with thin plastic films, the selection of the power, the circular cooling of the electrolyte solution, etc. Treating the whole pool shell with such measures, the abilities of the corrosion-proof and protection were greatly improved. The nuclear reactor has run for 37 years (from 1964 to 2001), by now the oxidization film on the surface of the pool shell is still bright. It can confirm that treating of the whole pool shell is successful and necessary, which can provide the help and reference for building the same model nuclear reactors.