Posttraumatic growth (PTG) is defined as positive psychological change in the wake of highly challenging circumstances. Healthcare workers in particular are more vulnerable to stressors and trauma than the general population. The current study examined the use and effectiveness of a novel positive psychological intervention based on Chinese traditional culture to improve PTG in hospital healthcare workers. The intervention was provided to 579 healthcare workers at hospitals in Guilin, Shenzhen and Xiangtan. Scores on the Posttraumatic Growth Inventory (PTGI) and its subscales were significantly higher after intervention than before (p < 0.001). Of the five aspects of PTG, the aspect of "new possibilities" benefited the most from intervention (Cohen's d = 0.45). PTG in women, nurses and college graduates increased to a greater extent than other participants after intervention. It was concluded that our novel intervention is effective at improving PTG in medical staff.