Abstract: Power which is scaled using 252Cf source conversion method, is an important benchmark experimental date in CFBR-Ⅱ reactor. The principle of the experiment of scale was introduced, and the power of measurement results was discussed. The factors which mainly affect the results of measurement are energy “corresponding gently” and “point source” assumed correct, and they were fully considered in the experiment. Through the power scale experiment, different indications at corresponding typical power level were obtained. The synthetic standard uncertainty of using the 252Cf source conversion method to scale power is 7%.