The invention provides a bidirectional detection protection method and
system for industrial control instructions and data transmitted in the same channel. The method comprises the following steps: acquiring
network communication flow between an upper computer and a
numerical control system; separating a control instruction or service data from the
network communication flow; determining the flow direction of the control instruction or the service data; if the flow direction is uplink, detecting the control instruction by adopting a first external intrusion detection strategy aiming at the control instruction, and detecting the service data by adopting a second external intrusion detection strategy aiming at the service data; if the flow direction is downlink, detecting the control instruction by adopting a first internal
anomaly detection strategy aiming at the control instruction, and detecting the service data by adopting a second internal
anomaly detection strategy aiming at the service data; and executing a corresponding
response strategy according to a detection result. The accuracy and the real-time performance of detection are remarkably improved, and the
system resource overhead and the
false alarm rate are reduced.