Abstract: The laser cutting and sealing of the radioactive light source was simulated by the finite element software Abaqus. The temperature distribution and thermal stress distribution of the glass tube of radioactive light source were obtained, under rotating conditions with time and different laser power irradiation. The analysis results show that the laser irradiation on the circumference of the glass tube can achieve the simultaneous melting of the whole tube, and the shorter sealing time was required as the laser power increased. Finally, the experimental results show that the simulated values of the cutting and sealing were consistent with the experimental values, which would provide guidance for the final establishment of the condition parameters of the laser cutting and sealing of the radioactive light source.