This study investigated the relationship between social support and the elderly gullibility risk. Social Support Revalued Scale,Interpersonal Trust Scale, Emotional-Social Loneliness Inventory and The Elderly Gullibility Risk Scale were administered to 198 elders to investigate the moderating effect of loneliness one the relationship between social support and gullibility risk, as well as the mediating effect of interpersonal trust on the moderation model. Result were as follows: 1) Social support positively predicted the gullibility risk of the elders. 2) Loneliness played a moderating role between social support and gullibility risk of the elders. 3)Interpersonal trust was the mediated variable in the moderating model of loneliness between social support and the elders’ gullibility risk. That is, improving the loneliness of the elders and reducing blind faith in others can reduce the gullibility risk effectively.