The invention discloses an analysis system and an analysis method for a network data packet. The analysis system comprises a to-be-recognized data packet capture unit, a data information acquisition unit and a to-be-recognized data packet judgment unit, wherein the to-be-recognized data packet capture unit is used for capturing a to-be-recognized data packet via Libpcao; the data information acquisition unit is used for acquiring data information of the to-be-recognized data packet via analysis; the to-be-recognized data packet judgment unit is used for judging a relationship between the to-be-recognized data packet and a preset application layer protocol link, and judging whether the to-be-recognized data packet is a normal data packet according to the relationship. According to the system and the method provided by the invention, a power system can learn the calling relationships of various interfaces according to the data packets, and thus acquires the network security state of thepower system.