Objective:To explore the psychological development process of suicide ideation-to-action in male prisoners,providing a basis for suicide prevention and intervention for them.Methods:Thirty-five male prisoners with self-reported or prison police assessment of suicide risk and history of self-injury and suicide were selected for in-depth interviews.Using grounded theory to code data,explore the evolution process and influencing factors of prisoners from suicidal ideation to suicide-related actions.Results:Prisoners were divided into three stages from the emergence of suicidal ideation to suicide-related actions,namely the seed stage of cumulative environmental effects(stage 1),the germination and development stage of suicidal ideation(stage 2),and the action strategy selection stage(stage 3).The process mainly contained 4 dimensions,namely situational risk factors,negative psychological experiences,psychological risk factors and psychological protection factors.Conclusion:The suicide psychological development process of prisoners is a gradual process.Suicide intervention should prioritize prevention,remove risk factors,enhance protective factors,and carry out personalized intervention based on different pathways.