Immunohistochemical diagnosis of cancer refers to the chemical examination method in pathology to further clarify the nature, growth rate and malignant degree of the tumor. Immunohistochemical diagnosis firstly requires puncture biopsy or surgical excision of cancer patients to obtain cancer cell tissues, and then initially determine the nature of the tumor through laboratory pathological diagnosis to make clear whether it is a benign or malignant tumor. At the same time, it can also determine the growth speed of the tumor and the differentiation degree of the tumor. Immunohistochemistry diagnosis is often applied to certain cancer patients with complicated conditions and not very typical, which can elaborate the characteristics of tumor cells from the molecular point of view.