Explosive power is an important factor in sports. The aim of this research is to design a sensor-based leg muscle explosive power instrument that is suitable with the characteristics of the explosive power, which has a working unit kg.m / s. and instruments that are effective, efficient and economical. development research was carried out by adapting the Borg & Gall model. This study involved 4 experts as validator tools for validation tests namely tests and measurements, exercise physiology, training science and IT. Data collected using a questionnaire. the results obtained from expert validation are an average percentage of 91%. The conclusion of this study is that the design and work of the developed instrument is acceptable or feasible to be developed.