Background Posttraumatic stress disorder (PTSD) symptoms after natural disaster can have a detrimental effect on marital relationships, which may be through parenting-related factor. Aims The study aimed to examine the mechanism underlying the long-term effects of PTSD symptoms on marital satisfaction via coparenting, and its differences between men and women following the Super Typhoon Lekima. Methods Participants were 465 married victims with children. They reported their PTSD, coparenting, and marital satisfaction at three and fifteen months after the tropical cyclone. Results The results showed that for women, only higher negative cognitive and emotional alterations (NCEA) symptoms were associated with lower marital satisfaction through conflict coparenting. For men, higher intrusion, NCEA, and hyperarousal symptoms were associated with marital satisfaction through different coparenting. To be specific, for men, higher intrusion symptoms were associated with lower marital satisfaction via less reprimand coparenting; higher NCEA symptoms were associated with lower marital satisfaction via less integrity coparenting, and associated with higher marital satisfaction via less conflict coparenting; higher hyperarousal symptoms were associated with lower marital satisfaction via more conflict coparenting. Conclusions These findings suggested that the long-term effect of PTSD symptoms on marital satisfaction via coparenting mainly showed for men.