The leadership of the principal as the person in charge, as a leader in the organization is needed to bring the goals of the organization that have been set. Teacher achievement becomes an important thing in determining the success of an educational institution, because it can be an indicator of the quality of a teacher. The leadership of the principal greatly determines the achievement of the teacher. Teacher achievement will be achieved if the principal supports the activities carried out by the teachers. The purpose of this study was to determine the effect of the principal's leadership on the teacher's work performance at SMKN 3 Lubuklinggau, and to determine the principal's managerial performance on the teacher's performance at SMKN 3 Lubuklinggau. This research method uses post facto with 90 teachers as respondents. Data collection was carried out by distributing online questionnaire sheets to all teachers of SMKN 3 Lubuklinggau. The data collection technique in this study was using a questionnaire. The instrument is made using a Likert scale, which is arranged in the form of a statement and is followed by a choice of responses that indicate the level. The instrument questionnaire to be used must be valid so that it can be used to detect exactly what should be measured. Instruments were analyzed using descriptive analysis with quantitative data analysis, using simple linear regression data processing. The results showed that the leadership of the principal of SMK N 3 Lubuklinggau was in the low category and had a negative value or had no effect on teacher work performance. The managerial principal of SMKN 3 Lubuklinggau in the High category and positive value states that there is an influence on teacher work performance. Principal leadership and managerial principals have a very weak effect on teacher work performance.