Abstract: NHR200-Ⅱ heating reactor is an integrated modular nuclear reactor with inherent safety, its design safety characteristics ensure that no large-scale leakage of core radioactive materials, making it technologically feasible to simplify the off-site emergency plan. Based on the research results of advanced reactors at home and abroad in emergency preparedness and the latest domestic regulatory requirements for small nuclear reactors, this paper calculates the dose consequences of a conservative BDBA for a certain plant site condition, demonstrates the feasibility of setting the emergency planning zone on the boundary of the plant, and puts forward some suggestions for the simplification of the off-site emergency plan.