This study aimed to explore whether there were differences in suicidal ideation at different time points among sexual minority men (SMM) within five years of HIV diagnosis, and to investigate the influence of time and psychosocial variables on suicidal ideation. This was a five-year follow-up study focusing on the suicidal ideation among HIV-positive SMM who were recruited when they were newly diagnosed with HIV. Suicidal ideation and psychosocial characteristics including depression, anxiety, HIV-related stress, and social support were assessed within one month, the first year, and the fifth year after HIV diagnosis. A total of 197 SMM newly diagnosed with HIV completed three-time point surveys in this study. The prevalence of suicidal ideation was 27.4%, 15.7%, and 23.9% at one month, the first year, and the fifth year after HIV diagnosis, respectively. The risk of suicidal ideation was lower in the first year than baseline, but there was no significant difference between the fifth year and baseline. Emotional stress and objective support independently predicted suicidal ideation and they had interactions with time. The suicidal ideation of SMM newly diagnosed with HIV decreased in the first year and then increased in the fifth year, not showing a sustained decline trend in a longer trajectory of HIV diagnosis. Stress management, especially long-term stress assessment and management with a focus on emotional stress should be incorporated into HIV health care in an appropriate manner. In addition, social support should also be continuously provided to this vulnerable population.