Today, the importance of happiness psychology researches has gained great importance due to the great role of this factor in maintaining health, satisfaction with life and strengthening the psychological dimension of man to deal with tensions and problems in the present age. Meanwhile, the topic of students' happiness, which is considered one of the main assets of any society, has naturally become more important. This research also aims to measure the effect of religiosity on the happiness of military students in a specialized military training center through a scientific research. The method used in the present research is descriptive and survey, the statistical population of this research is all the students of the specialized military training center who studied in the first half of the academic year 2019-2019. The sample population corresponds to the statistical population with a total of 110 people. The measurement tool consists of a 53-question questionnaire, which was prepared based on the ideas presented in this field and previous researches and seeking opinions from experts, and its Cronbach's alpha was 0.88. After collecting the data, it was analyzed using two test models (external and internal) in smart pls software. Finally, the general model was also examined and confirmed. The results showed that the effect of religiosity on the happiness of the students of the specialized military training center has a very significant effect, and religiosity includes more than 60% of all the factors affecting the happiness of the students of the training center.