In 1919，the Communist International was founded based on the needs of the revolutionary situation. During its existence，the Communist International vigorously spread Marxism-Leninism，helped build communist parties in many countries，established an anti-fascist united front，and promoted the development of international communist movements. But the Communist International also had some disadvantages in the organization and management systems，which produced some adverse effects. On the occasion of the 100th anniversary of the founding of Communist International，it is of practical significance to studying Communist International by reviewing its historical achievements，drawing lessons from it，exploring more appropriate ways of cooperation in the world socialist movements and promoting the development of world socialist movements.