This study investigated the effects of different salts and physical micro-particles on the trap discoloration and substance absorption mechanisms of Aldrovanda vesiculosa. Microscopic observations revealed three types of glands on the trap epidermis: digestive gland transfer cells on the inner epidermis, quadrifid gland hairs, and bifid trichomes on the outer epidermis. Feeding and centrifugation experiments showed that the traps do not close spontaneously, and the rate of red ink fading can be used as an indicator of absorption activity. The feeding process can be divided into three stages: capture, secretion, and absorption. High salt concentrations accelerated discoloration within 30 minutes, while moderate concentrations of micro-particles also enhanced the absorption rate within one hour. Some PVC micro-particles were later observed to enter the petiole region, suggesting the plant’s capacity for uptake. The results suggest that bifid trichomes, in addition to their defensive and secretory functions, may also sense changes in salinity and particle concentration, participating in osmotic and absorptive processes. Further elucidation of the trap’s closure-trigger mechanism could contribute to the development of biomimetic valve devices and microfluidic control systems.