Abstract: Strong ⁶³Ni source can be widely used in vacuum electronic devices, ion mobility spectrometer, gas chromatography, isotope battery and other fields. Some areas such as ⁶³Ni isotope battery, ⁶³Ni activity are important for the evaluation of battery conversion efficiency, but its activity measurement is rarely studied. To solve the difficulty of directly measuring strong ⁶³Ni source activity, based on the relationship between the activity and quality of radioactive material, the indirect measurement method was proposed by weighing for the activity of strong ⁶³Ni source prepared by electroless nickel plating process. The results showed that the mass of the ⁶³Ni coating with different numbers was between 0.92-2.16 mg. According to the specific activity of ⁶³Ni and the Ni content in the coating, the activity of strong ⁶³Ni source was calculated from 4.1×10⁸ Bq to 9.6 × 10⁸ Bq. Considering the system error of the balance and Ni content analysis, the reliability of the activity data was approving.