Cancer immunotherapy is a drastic and crucial topic in the medical field since it acts a vital role in cancer treatment. As several types of clinical and preclinical strategies have been advanced by the scientists, which are designed to respond to different kinds of cancers situations, we are still plagued by some adverse side effects brought by those existing therapeutic tactics. In the following part, we would review the so-far development of cancer immunotherapy and discuss their characteristics and potency. Furthermore, we would critically posit the barriers for today's techniques and analyze immunotherapy's future prospects.