Nowadays vocational education has undergone a number of significant changes which were the result of serious socio-economic changes in society as well as integration processes in European educational space. In modern education, practical classes began to occupy a significant part of the time of students' education. Therefore, an objective need arose in making changes to the existing system of vocational education, which will meet modern requirements for training highly qualified specialists. In the context of increasing importance of the practical part of education, the authors emphasize the need to focus attention on the practical work of engineering students as one of the most popular specialties of secondary vocational educational institutions which actualizes consideration of this issue in the work. The purpose of the article is to consider the improvement of practical work in the course "Power sources for welding" as fundamental in the training of welders. The authors developed a practical lesson in this course which is accompanied by appropriate detailed recommendations on the implementation of tasks. Improving students’ practical activity is an integral part of college successful functioning because within the framework of the competence-based approach, the training system must be transformed and adjusted to the requirements of the new Federal State Standard. Guided by the results obtained during the study, we concluded that this development can be used in the further process of teaching students in technical colleges in the city of Nizhny Novgorod.