The purpose of this study was to develop teacher-training for improvement of teaching efficacy of technology teacher. The study was carried out through Delphi research method. It was executed for investigating the professional and wide-range opinions of expert panel to examine the validity. The validity was confirmed by concurrence ratio, convergence ratio, contents validity ratio (CVR). Major results of this study were as follows: First, necessity, nature, purpose of teacher-training for improvement of teaching efficacy of technology teacher was set up. And this teacher-training have 12 objectives in 3 domains (cognitive, affective, psychomotor). Second, contents of this teacher-training were designed to be applicable for 10 modules (300 hours). For example, module1 (introduction of technology education), module2 (construction technology), module3 (information communication technology), etc. Third, educational method, training educator, evaluation method of this teacher-training were developed. Fourth, each module of this teacher-training is 30 hours in length. And summer or winter vacation is appropriate for this teacher-training time. Appropriate teacher-training time is six hours a day. Fifth, roles of educational institution for this teacher-training were suggested. Sixth, strategies to vitalize this teacher-training were suggested.