Olfaction visualization technology is a gas imaging technology and a new branch of artificial olfactory technology, which can solve common problems of traditional gas sensor. In order to detect the dominant spoilage bacteria (Clostridium, Brochothix thermosphacta and Pseudomonas) and evaluate freshness of pork, porphyrins and pH indicators were used as gas-sensing materials. The three spoilage bacteria were inoculated into three groups of pork samples and stored under three temperatures (16,4℃and 20℃). The images before and after the colorimetric sensor array interacted with pork's volatile flavors were collected, then image processing techniques was used to get digital signals which reflected the freshness of pork. The results showed that the olfaction visualization technology can be applied in rapid detection of dominant spoilage bacteria and evaluation freshness of pork.