This research was motivated by two main problems: (1) the ineffectiveness of courageous learning is often caused by technical problems; and (2) the learning model used by teachers so far has not been effective, innovative, and optimal because it still uses a textual-based problem-based learning model. The purpose of this study was to develop a problem-based blended learning model for computer network engineering subjects at vocational education and to test the validity, practicality, and effectiveness. The development model applied in this study is the 4D development model, namely: (1) define, (2) design, (3) develop, and (4) disseminate. Data collection techniques were carried out through questionnaires to get validation experts, the practicality of teachers and students. Furthermore, the effectiveness of the data was done through a comparison of pretest and posttest values. The results of the calculation of the acquisition of a score reached 0.53 in the moderate category. Therefore, it can be concluded that the learning model of blended learning based on problem based learning in the subjects of computer network engineering in Vocational High Schools has a high level of validity, practicality, effectiveness.