Abstract: Forestry industry is one of the sources of national economy and its development is closely related to people's livelihood. Therefore, the stability of forest farm staff is an important guarantee to ensure the smooth development of forestry. This paper explores the occupational psychological mechanism of forest farm staff from the psychological perspetive. A total of 450 questionnaires were delivered to three state-owned forest farms, and 387 questionnaires were valid, i. e., the recovery rate was 86%. The results validated the double-path model of job-related characteristics affecting the forest farm staff's happiness experiences, the job demand positively predicted subjective well-being and emotional well- being of staff. The job demand affected the happiness of staff by the mediation of job-family conflict. The more the job demand was, the more the job-family conflict was, job resources played a regulation role in the process of job demand affecting job-family conflict. Job resources positively predicted the subjective well-being and emotional well-being of forest farm staff; the job demand affected the happiness of staff by the mediation of job-family promotion. Personality traits demonstrated moderating effects on the dual-path model, specifically, the extroversion and pleasantness of the personality traits buffered the negative impact of job-family conflict on the happiness experience, the pleasantness had a moderating effect on the relationship between job-family promotion and happiness, and the pleasantness increased the positive impact of the job-family promotion to the happiness experience.