Abstract: Based on the subtidal macrobenthos data obtained from 16 sampling stations in Xinghua Bay, Fujian in June 2019, 16 sampling stations in Daya Bay, Guangdong in March 2021, and 15 sampling stations in the subtidal zone near Changjiang Nuclear Power Plant, Hainan in December 2018. The grappler method risk index (GMRI) of a total of 20 species of macrozoobenthos in three subtidal zones were calculated to evaluate the potential risk level of these 20 species of macrozoobenthos blocking the nuclear power cooling source system. The results showed that the GMRI of Stolus buccalis in the subtidal zone of Xinghua Bay, Fujian in June 2019, Timoclea scabra in March 2021 in the subtidal zone of Daya Bay, Guangdong, and Aglaophamus dibranchis in December 2018 in the subtidal zone near Changjiang Nuclear Power Plant was 63.78%, 65.52% and 50.86%, respectively, which were in the middle risk level. The GMRI of Lumbrineris sp., a common species in all three subtidal zones, ranged from 41% to 48%. The GMRI of Prionospio pacifica and Amphioplus laevis in the subtidal zone of Daya Bay were 46.65% and 45.80%, respectively. It was higher than the GMRI of Prionospio pacifica and Amphioplus laevis in the subtidal zone in Xinghua Bay and near Hainan Changjiang Nuclear Power Plant (between 32%～37%). The GMRI of Acaudina molpadioides in the subtidal zone in Daya Bay and near Changjiang Nuclear Power plants was 41.45% and 41.42%, respectively.