Consuming too much salt greatly increases the risk of heart disease and stroke, and limited studies focused on knowledge of salt intake in relation to salt consumption. Our study aimed to investigate salt intake and knowledge of salt intake in a Chinese population. Altogether 42114 adults aged 18 years and above were selected by multi-stage cluster sampling method. Salt consumption and knowledge of salt intake were assessed by self-reported questionnaire. The average salt intake was 15.5 ± 11.9 g/d, and 85.2% of subjects with excessive salt intake. Almost 80% of dietary salt came from salt, followed by salty vegetable (13.5%) and soy sauce (3.3%). There were 28.3% participants knowing the National recommended salt intake, and 29.7% with knowledge of excess salt intake resulting in hypertension. Overall 57.6% participants had ever been received health education on low-salt diet. After adjustment of confounders, subjects without knowledge of salt intake had a higher risk of excessive salt intake. Salt intake is high in the Chinese population. Awareness of salt intake is low, and it is inappropriate with current health education.