Abstract： The tumor immune microenvironment （TIME） plays a critical role in the occurrence， development， and metastasis of malignant tumors，and its immunosuppression is a key cause of tumor immune evasion and therapeutic resistance. According to the cancer toxin theory in traditional Chinese medicine，cancer toxin is a specific pathological product of malignant tumors that intermingles with phlegm， stasis， and heat pathogens， consuming healthy-qi and impairing the functions of the zang-fu organs and qi-blood. Based on the cancer toxin theory，this article proposes that the core pathogenesis of TIME lies in：cancer toxin damaging healthy qi，leading to immune imbalance，corresponding to impaired immune surveillance and suppressed immune cell function in TIME；intermingling of phlegm，stasis，and toxin causing microenvironmental disruption， involving obstruction of collaterals and brewing of heat toxin， corresponding to chronic inflammation，hypoxia，and overall microenvironmental disorder in TIME；and the migratory， aggressive，and tenacious nature of cancer toxin driving malignant remodeling of TIME，promoting tumor progression， metastasis，and drug resistance. Traditional Chinese medicine regulates TIME through multiple targets via therapeutic approaches such as clearing heat and removing toxins，dissipating phlegm and resolving masses，activating blood and dissolving stasis， and fortifying healthy qi and consolidating the body-constitution. By systematically exploring the mechanism and clinical approach of traditional Chinese medicine in regulating TIME， this article aims to provide a theoretical basis and new perspectives for traditional Chinese medicine-based prevention of malignant tumors.