Objective To evaluate the effect of nutritional health knowledge， attitude and practice theory on seafarers’ health education intervention.Methods A total of 628 seafarers who underwent health check-up in two designated hospitals in Zhoushan in 2019 were selected as subjects. They were divided into two groups by cluster random sampling method. Nutritional health intervention with different methods was conducted for one year， followed by another health check-up in 2020 and 2021. Dietary nutritional status survey was carried out in both groups during physical examination.Results After intervention， the daily intake of grain， potato， mixed beans， vegetable， fruit， soybean and nut in the intervention group was significantly higher than that in the control group， while the daily intake of edible oil in the intervention group was significantly lower than that in the control group （P<0.05）. The daily protein intake of sailors in the intervention group was significantly higher than the control group （P<0.05）. The abnormal detection rate of physical examination results after intervention was 76.0%， significantly lower than that before intervention （92.0%） （P<0.05）. Topsis comprehensive evaluation showed that the Ci value of the intervention group was significantly higher than that of the control group and closer to 1 （P<0.05）.Conclusion Dietary nutritional status and physical examination results of seafarers can be improved by nutritional KAP intervention. Nutritional KAP intervention can effectively protect seafarers’ health.