Objective To explore the current status, influencing factors and the role pathways of young and middle-aged diabetic patients′ shared decision-making, to providing a reference for patient shared decision-making research and intervention. Methods A general information questionnaire, the Perceived Social Support Scale, the Decision Making Self-Efficacy Scale, the eHealth Literacy Scale, the Brief Illness Perception Questionnaire, and the 9-item Shared Decision Making Questionnaire were used to investigate 215 young and middle-aged diabetic patients. Structural equation modeling was used to analyze the influencing factors and the pathways of shared decision-making. Results The shared decision-making score of young and middle-aged diabetic patients was 85.36±13.23. Illness perception, eHealth literacy, perceived social support, and decision-making self-efficacy were influencing factor of patients′ shared decision-making, with total effects of -0.345, 0.280, 0.274, and 0.163, respectively (all P<0.05). Illness perception, eHealth literacy, and perceived social support indirectly influenced shared decision-making through decision-making self-efficacy (all P<0.05). Conclusion The level of shared decision-making among young and middle-aged diabetic patients is in the middle to high range, and patients′ decision-making self-efficacy can positively influence shared decision-making and also can exert an indirect effect on the level of shared decision-making. Ruducing patients′ negative illness perception, improving eHealth literacy, perceived social support, and decision-making self-efficacy can increase patients′ participation in shared decision-making.