The purpose of this study was to develop principal technology leadership competency indicators for technical high schools in K-12 in Taiwan in order to improve the effectiveness of school administration and teaching. In the first part of the study, five experts in the technology leadership field are interviewed to explore the technology leadership theorem model. In the second part of the study, eighteen experts in technology leadership and principals of technical high schools are recruited as subjects. Using the Delphi technique, questionnaires are constructed to assess competency indicators for principal technology leadership. In the third part of the study, the data from the questionnaire are analyzed using a KS-test and Kruskal-Wallis one-way analysis of variance by ranks. Finally, six dimensions and thirty competency indicators of the principal technology leadership of technical high schools in K-12 in Taiwan were established.