Agricultural certificates, such as green or organic product certificates, can help agricultural food companies to reduce information asymmetry along supply chain. With high quality and safety, these products have greater market stability than non-certified products when exposed to food safety scandals. However, certified food products are still not so popular because common consumers are unfamiliar with and not willing to pay for high price. Information disclosure is considered to be an effective way to improve consumers’ trust level and their willingness to pay (WTP), therefore their consumption of certified food could be increased by providing with some information stimulation under food crisis. African swine fever (ASF) has posed a serious threat to the Chinese pork industry ever since it broke out in the country. However, it may have a positive effect on the promotion of certified pork. This paper attempts to explore how to implement information intervention to increase consumers’ WTP for certified pork in the context of a food crisis related to ASF, via providing different forms of information stimulation. Previous studies have focused on the detail content and sources of information, but few have investigated the intensity of information stimulation. In addition, in what degree of the food safety crisis affecting the development of the certified food industry remains unknown. To fill in this gap, an investigation was conducted in major pork consumption cities in China, and two different information stimulation groups (negative and balanced), and one as control were established on the basis of mass media reports on the ASF epidemic in China. The negative information listed the harm and current situation of swine fever, as well as negative news about branded pork exposed to ASF, and the balanced information included some positive information from experts to counter the negative information, while the control group did not contain any related news. The intensity of information stimulation in this work is represented by an index of possible experiences involving the purchase of diseased pork. We first employed the ordered probit model to verify that consumers were more willing to purchase certified food than non-certified food after epidemic information stimulus. Then a contingent valuation method was designed to verify the influence of trust level and intensity of information stimulation on consumers’ WTP for certified pork, including individual consumers’ characteristics as control variables. And then we calculated the marginal values of trust level and information stimulation intensity among different age groups. Based on the data from 706 valid questionnaires, the results show that consumer trust level and purchase frequency of certified pork were higher than those of non-certified pork under negative information stimulation, and trust level and information stimulation intensity had positive relation with consumption of certified food. In balance information groups, consumers’ trust level and purchase frequency of non-certified pork rose. After stimulated by negative information, consumers had a lower WTP for certified pork than those of WTP in the control group, while the effect of their trust level on WTP for certified pork would be enhanced under a higher intensity of information stimulation. However, this kind of moderating effect did not exist in the balanced information group. Young consumers with high levels of trust, as well as the richer ones were more willing to pay higher prices. From this point of view, food safety accidents can play a positive role in the promotion of certified food to a certain extent. The policy makers should actively provide guidance on food safety and promptly organize experts to explain the pros and cons to the public whose intensity of information stimulation would be increased with a clear understanding of food crises. Furthermore, it is essential to inform the public, especially older consumers about certified food, to improve their trust level.