Objective  To explore associations of social support, perceived loneliness, and coping style with mental health among only-child-lost people in Baoji city of Shaanxi province and to provide references for conducting mental health education among the people.

  Methods  Using stratified random cluster sampling, we conducted a questionnaire survey among 249 only-child-lost people aged > 49 years in urban regions of Baoji city during August 2016. Kessler Psychological Distress Scale (K10), Social Support Rating Scale (SSRS), University of California at Los Angeles (UCLA) Loneliness Scale (UCLA-LS), and Simplified Coping Style Questionnaire (SCSQ) were adopted in the study.

  Results  The mean K10 score was 24.37 ± 9.92 for all the participants and 51.0% of the participants were assessed at a high risk (20.1% 50 at risk level 3 and 30.9% 77 at risk level 4) of having mental illness. There were a significant reverse correlation between SSRS score and K10 score (r = – 0.304, P < 0.01) and a positive correlation between UCLA-LS score and K10 score (r = 0.525, P < 0.01). Stepwise linear regression analysis revealed that perceived loneliness and positive coping exerted impacts on mental health in the participants.

  Conclusion  The only-child-lost people′s mental health could be promoted by social support and predicted by perceived loneliness and the perceived loneliness plays a mediating effect on associations of positive coping and social support with mental health among the only-child-lost people.