This is a prospective, single-arm, open, single-center clinical trial to evaluate the safety and efficacy of autologous NK cells combined with chemotherapy and GD2 monoclonal antibody in the treatment of newly diagnosed high-risk or relapsed/refractory neuroblastoma in children. Fifteen eligible subjects are planned to be included. The objective is to evaluate the safety and efficacy of autologous NK cells combined with GD2 monoclonal antibody in the treatment of children with newly diagnosed high-risk or relapsed/refractory neuroblastoma, which is expected to be safe and effective in improving PFS and DCR in children with refractory/recurrent neuroblastoma.