In combat sports, competition preparation is crucial, but research on this topic has been limited due to a lack of measurement tools. This study aimed to develop and validate the Multidimensional Assessment of Preparation for Sport Competition (MAPSC). In the first step, 61 athletes and 39 coaches collaborated to conceptualize and develop preliminary items, resulting in five domains (psychological, physical, emotional, environmental, and informational preparation) and the creation of 52 preliminary items. The second step collected data from 608 student-athletes and utilized exploratory and confirmatory factor analysis to test internal validity. The MAPSC was structured to include five-factors and 25 items. Finally, the correlations between MAPSC, self-management, and sport confidence, as well as differences in MAPSC based on winning experience in national competitions, were tested. In conclusion, MAPSC has been developed and confirmed as a valid measurement for assessing competition preparation strategies in combat sport. Coaches and athletes can use this tool to prepare for competitions systematically and strategically.