Invasive fungal disease (IFD) is one of the serious complications after hematopoietic stem cell transplantation (HSCT), characterized by high incidence and high mortality. According to the data from a multi-center study in China (CAESAR 2.0), even with the extensive use of antifungal active drugs for prevention, the cumulative incidence of IFD one year after HSCT still reached 6.3%, and the IFD-related mortality rate was 48.28%. In recent years, with the improvement of transplantation techniques, the application of new antifungal drugs and the optimization of diagnostic methods, the pathogen spectrum and clinical characteristics of IFD have undergone significant changes. Compared with ten years ago, the proportion of non-Aspergillus pathogens (such as Candida and Mucophora) has significantly increased, while the proportion of Aspergillus has relatively decreased. In addition, different types of invasive mycosis (such as invasive aspergillosis and invasive fusarium) show significant differences in clinical manifestations, onset time and prognosis. However, at present, large-scale prospective cohort studies on IFD after HSCT in China are still relatively scarce, and the diagnosis and treatment norms and prevention strategies in clinical practice still need to be further optimized. This study intends to conduct a multi-center retrospective and prospective combined longitudinal cohort study to comprehensively register the basic information, diagnosis, treatment and prognosis of IFD patients after HSCT, providing evidence-based medical basis for establishing new clinical diagnosis and treatment technologies and improving the long-term survival rate of patients.