Adolescence has always been regarded as a period of rapid psychological and behavioral change. Adolescents are subject to more difficult behaviors, and those difficult behaviors have a great impact on co-parenting and parenting burnout. In order to reveal the relationship between these factors, this study investigated the mediating effect of difficult adolescent behaviors on that relationship by constructing a theoretical model and examined the moderating effect of family functioning. In order to provide a scientific basis for preventing and intervening in adolescents' problematic behaviors and improving parents' parenting burnout, we conducted a study on the parents of 1638 teenagers in a junior high school in Huanggang City, China in May 2023, with a questionnaire filled out by the parents. The research tools included a parenting burnout questionnaire, Parental collaborative parenting Scale (PPCR), Adolescent Strengths and Difficult Behaviors Questionnaire (Parental Version), Family Function Scale, etc. An independent sample t test and ANOVA test were used to analyze whether there are certain demographic variables in parenting burnout, and SPSS27.0 was used for descriptive statistics, reliability and validity tests, correlation analysis and common method deviation tests. The adjusted mediation model was tested by using the SPSS macro program Process4.0. Results: The variance in the explanatory capacity of the largest factor in this study was 21.955%, which did not exceed the critical value of 40%, so there was no obvious common method deviation in the data of this study. The independent sample t test and ANOVA test showed that there are certain differences in parental rearing burnout dependent on parental gender, the main caregivers, family economic income and demographic variables. The results of the adjusted mediation model test by Process4.0 show the following: (1) Adolescent difficult behavior plays an intermediary role between parental collaborative parenting and parenting burnout; (2) the indirect effect of collaborative parenting on parenting burnout through adolescents' problematic behaviors is regulated by family functions; (3) the relationship between adolescent difficult behavior and parenting burnout is regulated by family function; (4) the direct influence of collaborative parenting on parenting burnout is also regulated by family function. Conclusion: Adolescents' difficult behavior partially mediates the influence of parents' collaborative parenting on parenting burnout. In addition, family function not only mediates the front and back ends of mediation, but also mediates the direct influence of collaborative parenting on parenting burnout. These findings are instructive for improving family parenting problems and promoting adolescent development. The results of this study may be helpful in enhancing parents' awareness of parenting of adolescents in China, which will provide reference for some teachers in China to understand adolescent behavior. At the same time, the results may provide new enlightenment for mental health professionals and enable them to fully understand the parenting contradictions between parents and adolescents in China.