Unlike general e-commerce, live streaming commerce innovatively allows live streamers to use instant social functions to communicate with viewers and present products in a more vivid way. However, little research has been done to understand the effects of multiple information cues in live streaming commerce. Drawing on the stimulus–organism–response (S–O–R) theory, we develop a two-phase research framework to examine how the combination of endogenous and exogenous cues can influence viewers’ information processing and arouse purchase intention when watching e-commerce live streaming. We also propose that product involvement may moderate the effects of information cues. To investigate the above effects, we conduct a laboratory experiment using self-report and functional near-infrared spectroscopy. In summary, the experimental results show that the richer the cues provided by the live streaming, the better the effect on viewers’ product knowledge accessibility for low-involvement products. However, complex information cues have a negative effect on the viewers’ cognitive processing of high-involvement products, which may distract viewers’ attention from the products and reduce consumers’ product knowledge accessibility. In addition, the introduction of the live streamer, the real-time comments, and the detailed product list aroused the viewers' positive emotions among the viewers and thus stimulated their purchase intention. These findings can help platforms, businesses, and live streamers improve their marketing strategies.