Abstract: As the important cultural center in the Tiananmen Square, The old China National Museum constructed in 1950's year had not fit in with the needs of modern cultural propaganda.Since 2004, t he seven years extension project of the China National Museum has brought new vigor to the historical and cultural construction.Through the careful design of the connection of the old building and the new building, the museum has been converted into a complete and modern large-scale exhibition building meeting the requirement of modern life, in which the original with precious historical value in the historical building has been protected as much as possible．