<p>Drug craving represents a persistent challenge in substance use disorder treatment, yet the psychological mechanisms underlying the relationship between drug addiction memory and craving remain insufficiently understood. This study examines whether meaning in life mediates the association between drug addiction memory and drug craving, and whether social support moderates these pathways, specifically within the context of China’s compulsory rehabilitation system. A total of 454 males from a state-administered drug rehabilitation centre in Nanning completed standardized assessments of drug addiction memory, meaning in life, drug craving, and social support. Using the SPSS PROCESS macro, a moderated mediation analysis controlling for sociodemographic attributes revealed that drug addiction memory positively predicted drug craving (<i>β</i> = 0.29, <i>p</i> &lt; 0.001), with 27.5% of this effect mediated by meaning in life. Social support significantly moderated both the direct pathway (<i>β</i> = −0.16, <i>p</i> &lt; 0.01) and the indirect pathway via meaning in life (<i>β</i> = −0.18, <i>p</i> &lt; 0.001). Specifically, drug addiction memory strongly predicted craving under conditions of low social support (<i>β</i> = 0.39, <i>p</i> &lt; 0.001) but demonstrated no significant association under high support (<i>β</i> = 0.11, <i>p</i> &gt; 0.05). Conversely, meaning in life exerted a stronger protective effect against craving when social support was high (<i>β</i> = −0.39, <i>p</i> &lt; 0.001) compared to when it was low (<i>β</i> = −0.05, <i>p</i> &gt; 0.05). These findings suggest that enhancing meaning in life and strengthening social support systems can buffer the impact of drug-related memories on craving in compulsory rehabilitation settings, highlighting the importance of integrating meaning-centred interventions with robust psychosocial support to reduce craving and improve treatment outcomes.</p>