Because salted fish will produce nitrite in the production process, it will become carcinogenic nitrosamines when it enters the acidic environment in the stomach. Studies have shown that eating salted fish is positively correlated with the incidence of esophageal cancer, gastric cancer and nasopharyngeal cancer. Another study shows that people who often eat bacon, salted fish or like to eat heavy salt have a higher relative risk of developing gastric cancer.
It is recommended not to eat it often. There's nothing wrong with eating occasionally.