Abstract: The fuel handling accident is one of the design basis accidents that are of major concern in the safety analysis of the modular small pressurized water reactor. Analyzing the key factors that affect the source term and dose of the accident is of great significance for determining and optimizing the exclusion area boundary. According to the radionuclide migration and release mechanism after fuel handling accident for modular small pressurized water reactor, the accident source term and radiation dose calculation models were established. The effect of water filtration function, dose conversion factor, release time from building to environment, decay time and shortterm atmospheric dispersion factor on the source term and radiation dose in fuel handling accident was studied. The results show that the external exposure dose of ground deposition is very small and could be ignored, because the release time in this accident is very short, and it only takes 2 h for the radionuclides to be completely released into the environment. Water filtration function not only affects the release amount of element iodine, but also affects the composition of various forms of iodine released into the environment, which has a significant impact on the personal effective dose and thyroid dose. From the review point of view, the calculation result is more conservative when the overall decontamination factor of iodine is 200. Whether the iodine dose conversion factor considers form difference has a greater impact on the inhaled internal radiation dose. The extending release time of radionuclides to the environment has significantly reduced the radiation dose after the accident. With the extension of the decay time, the radioactivity released into environment, personal effective dose and thyroid dose gradually decrease. In the offsite boundary dose evaluation, it is necessary to pay attention to the constraint of the thyroid dose limit. Due to the difference between calculation models and meteorological data, the shortterm atmospheric dispersion factor calculated by PAVAN code is about 610 times larger than that of ARCON96 code within a range of 100500 m. The shortterm atmospheric dispersion factors calculated by different codes have a great influence on the determination of the exclusion area boundary. The PAVAN code is conservative in the estimation of relative concentration in the vicinity of the site (less than 500 m). The source term and radiation dose of the fuel handling accident should be calculated according to RG1.183, the recommended dose conversion factors of ICRP71 report and the reasonable shutdown decay time to ensure the conservativeness and rationality of the calculation results. The ARCON methodology provided by RG4.28 can be used to calculate the shortterm atmospheric dispersion factors at the exclusion area boundary (<1 200 m).