Objective To investigate the preoperative psychological states of patients undergoing extracorporeal shockwave for osteonecrosis treatment of the femoral head inside out. Methods Purposive sampling method and semi-structured interviews were conducted in 12 patients who would be undergoing extracorporeal shockwave treatment of osteonecrosis of the femoral head in China-Japan Friendship Hospital. The data was analyzed using phenomenological method. Results The preoperative psychological states of patients were summarized into four themes: imperceptions of disease, insufficient understanding of extracorporeal shockwave treatment, uncertainties of treatment effects, and over expectation for the prognosis after treatment. Conclusions Nurse needs to provide specific preoperative propagandization and psychiatric mental health nursing for patients before extracorporeal shockwave treatment, and improve quality of nursing service.