The Electric Power System is one of the competencies that must be mastered by vocational teachers in Electrical Power Installation Engineering fields. However, many vocational teachers have difficulty in distance learning, both in theory and practice, during the Covid-19 pandemic. This article discusses efforts to increase the competence of vocational teachers in the electricity sector through the implementation of training on Android-based Electric Power System Learning Media Development. The training program is designed online through the Zoom Meeting application. The training method uses an andragogy learning approach that combines lectures, demonstrations, exercises, evaluations, and mentoring. The training material consists of the concept of an electric power system which includes components of the electric power system, modelling of the electric power system, analysis of the electric power system, engineering learning media, learning media with android applications, and how to compose electric power engineering learning media based on Android applications. This training can improve the competence of vocational teachers in the field of electric power systems. The indicator of teacher competency improvement is indicated by the increase in test scores from 72.04 to 77.67.