Using S-O-R model, this study explores the triggering mechanism of phishing sensitivity caused by security warning deterrence, security knowledge guidance, and security warning deterrence + security knowledge guidance. Study 1 explores the triggering effect of these three types of stimuli on phishing sensitivity through online experiments, and considers the moderating effect based on phishing situation. The results show that knowledge guidance and warning deterrence + knowledge guidance have significant triggering effects on phishing sensitivity, whereas warning deterrence has no such effects. The phishing situation plays a moderating role. In study 2, a cognitive neural experiment is conducted. The functional near-infrared spectroscopy (fNIRS) technology is used to explore S-O-R triggering mechanism of phishing sensitivity mediated by cognitive processing and trust. The results show that both cognitive processing and trust play a mediating role between security intervention and phishing sensitivity. The research results have important theoretical value and practical significance for improving phishing sensitivity.