Artificial intelligence is a man-made device that simulates intellectual work such as human thinking and judgment. There are many successful applications of artificial intelligence in the fields of medicine, healthcare, agriculture, education, finance, service, news and machinery. Intelligent computer hospital management systems, intelligent medical diagnostic expert systems and intelligent surgical robots have revolutionized the medical field. Therefore, the attentions which are paid to artificial intelligence in cancer diagnosis and cancer treatment are on the rise. Some breakthroughs have also been made in the application of imaging diagnosis, pathological diagnosis, oncology surgery, oncology radiotherapy, drug development and cancer screening. Artificial intelligence is gradually changing the traditional medical model, which is a future direction and trend of human medical development. Here, we delineate the concept and development of artificial intelligence, and its application and prospect in the diagnosis and treatment of malignant tumors.