Abstract: MHT scale is adopted to investigate the mental health between the rural left-at-home children and the non-left-at-home children in junior high school in Shaanxi Province. Results indicat that: outdoor-workers parents produce unfavorable effects on the left-at-home children mental health; the MHT total scores of the left-at-home children are prominently higher than the score of the non-left-at-home children; specifically, tendencies of loneliness, self-blame tendencies and allergic tendencies of the left-at-home children are significantly different; different left-at-home states have different effects on the children’s mental health; the mental health levels of the female left-at-home children are prominently lower than the level of the male left-at-home children. Finally, the countermeasures are put forward from three aspects of family, school and social education.