Non-suicidal　self-injury　(NSSI)　is　an　emerging　concern　in　the　field　of　public　health.　The　objective　of　this　study　is　to　develop　a　conditional　process　model　to　investigate　the　relationship　between　social　anxiety　and　NSSI,　and　the　role　of　impulsiveness　and　self-esteem　in　this　relationship.　A　convenience　sample　of　2717　university　students　(Mage　=　19.81,　22.49%　male)　from　Southern　China　was　recruited.　The　age　range　of　the　participants　is　between　18　and　25　years.　The　data　were　analysed　using　Spearman　correlation　analysis,　mediation　analysis　and　moderation　analysis.　The　study　revealed　a　positive　correlation　between　social　anxiety　and　NSSI,　with　impulsiveness　serving　as　a　mediating　factor　in　this　association.　The　relationship　between　social　anxiety　and　NSSI,　impulsiveness　and　social　anxiety,　impulsiveness　and　NSSI　were　all　found　to　be　moderated　by　self-esteem.　The　prevalence　of　NSSI　among　college　students　exhibited　a　strong　association　with　social　anxiety　and　impulsiveness.　The　present　investigation　additionally　demonstrated　that　there　was　no　significant　association　between　social　anxiety,　impulsivity　and　NSSI　when　high　self-esteem　was　included.　This　finding　implies　that　self-esteem　plays　a　crucial　role　in　safeguarding　against　NSSI.　©　2024　International　Union　of　Psychological　Science.