Abstract: To study the level of radiation dose on nuclear medicine of radionuclides with estimation method. We chose some diagnostic and therapeutic radionuclide to estimate the dose of internal radiation and external exposure with the estimation model of the dose coefficient method and point source. The results showed that the effective dose that patient suffered in a single diagnostic CNM procedure was up to 1.63 Sv; the single effective dose that A and B medical staffs suffered were 1.48 μSv and 1.15 μSv. The dosage level of some part of Diagnostic radionuclide beyond medical guidance level. The estimation results was slightly larger than the measured effective dose, less than other estimation. Combined with the actual situation, the estimation model can be used as an effective estimation method of the radiation dose level of nuclear medicine radionuclide.