Tumor immune microenvironment (TIME) plays an essential role in tumor occurrence and development. Whether anesthesia techniques and anesthetics will change the tumor immune microenvironment so as to affect the short⁃term/long⁃term progno⁃ sis of cancer patients has become the focus of attention. This article reviews and summarizes the literature on the effects of anesthesia on the tumor immune microenvironment to provide a reference for clinical treatment and research. Inhaled anesthetics, intravenous an⁃ esthetics, opioids, and local anesthetics will all change the function of the tumor immune microenvironment to varying degrees, thereby affecting tumor growth, metastasis, and the short⁃term/long⁃term prognosis of patients. The hypothalamic⁃pituitary⁃adrenal axis (HPA axis), cellular immunity, and cytokine expression are related to changes in hypoxia inducible factor⁃1α (HIF⁃1α) activity. Several in vi⁃ vo/in vitro experiments have confirmed that different anesthesia methods and anesthetics can cause changes in the tumor immune mi⁃ croenvironment. Still, prospective randomized controlled trials with a large sample size are also required to confirm the relationship be⁃ tween the change in tumor immune microenvironment and the prognosis of tumor patients.