A principals' school management imaginative capability is the cornerstone of visionary leadership. Based on the imagination theory, this study constructed a Principal's School Management Imaginative Capability Scale (PSMICS). Questionnaires were conducted through stratified random sampling. Thirteen hundred and two valid samples were obtained. PSMICS is a three-factor model with a total of 16 items, which demonstrated excellent model fit. The factors measured by each item conform to the theoretical construct. The scale has good reliability in terms of internal consistency. The recheck validity test shows that the scale model is stable. Theoretical implications, educational implications, limitations and scope of future research are provided.