The invention discloses a steam drying system for papermaking drying part. The steam drying system comprises a first drying mechanism and a second drying mechanism. The first drying mechanism and the second drying mechanism each comprise a drying cylinder set. The first drying mechanism is provided with a first air inlet and an exhaust port. The second drying mechanism is provided with a second air inlet and a steam inlet. The first air inlet and the second air inlet are communicated through a steam pipe. A steam inlet is formed in the steam pipe. The exhaust port and the steam inlet are communicated through a hot air duct. The problem that according to an existing technology, the steam consumption of a papermaking drying part is large is solved, and the steam drying system can lower the steam consumption.