To demonstrate the effectiveness of health-promoting school framework to promoting healthy eating behaviours and nutrition knowledge among Chinese middle school students, their parents and school staff. Three schools were randomly selected from 15 rural middle schools, then were randomly assigned to either (i) school using HPS framework (HPS school), (ii) school with improved health education only (HE school) or (iii) school received no intervention (control school). Nutrition knowledge and eating behaviours were measured at baseline and 3-month after interventions, using the same instrument. Students and parents in the HPS school had the largest improvement in nutrition knowledge, from 4.92 to 8.23 and 4.84 to 7.74, followed by those in the HE school, from 4.98 to 8.09 and 4.78 to 5.80. School staff in the HE school had the largest improvement in nutrition knowledge (from 4.40 to 8.45), followed by those in the HPS school (from 5.20 to 9.15). Students in the HPS school had the largest improvement in eating behaviours (from 3.16 to 4.13), followed by those in the HE school (from 2.78 to 3.54). There was a statistical difference in the improvement of nutrition knowledge of all target population and of eating behaviours of students after interventions across three schools (p < 0.05). Both HPS framework and health education can increase nutrition knowledge among Chinese middle school students, their parents and school staff. However, HPS framework was more effective than health education only. Noticeably, HPS framework had a positive impact on students' eating behaviours, which should be in the subject of further research.