Wildlife feces are a valuable noninvasive resource in ecological and conservation research. However, traditional preservation methods are unable to maintain morphological integrity while simultaneously preserving the biological and chemical composition of fecal samples. This study introduces a novel method for the preparation of fecal specimens through a multistep infiltrated process using sodium carboxymethyl cellulose, sodium benzoate, clotrimazole, ethanol, pyrethroid emulsion, and polyvinylpyrrolidone solution. The entire procedure takes approximately 7 days to complete one batch of specimens. The specimens produced using this method exhibited high mechanical strength, ensuring durability and resistance to handling damage. Over an 18-month storage period, the preserved specimens retained their external morphology and showed no signs of mold or insect damage. DNA integrity was well maintained, with a 100% success rate in DNA extraction, and species identification based on preserved specimens was identical to that obtained from the corresponding pre-preservation feces. Furthermore, heavy metals such as chromium, arsenic, and lead were successfully detected in fecal samples from different species. By allowing long-term preservation of fecal samples, this method converts feces from a transient diagnostic tool into a durable resource for monitoring biodiversity. It can broaden the spatial and temporal applicability of fecal samples and strengthen their role in ecological research and biodiversity conservation.