Compound helicopters are classified into five classes according to their rotor technologies and compound propulsion styles. In addition, the developments of the five classes of compound helicopters are briefly introduced, and it is divided into five stages based on technology readiness level and market demands. The developped patterns of overseas compound helicopters are summarized. Eventually, based on foreign experiences of compound helicopter dvelopment, domestic helicopter technological capacities and mechanisms in scientific research, some pieces of advice on domestic compound helicopter development are presented.