At　present,　intrusion　detection　system　over　fieldbus　network　layer　was　a　basic　protection　method　in　industrial　control　system.　However,　it　has　some　weakness,　such　as　poor　generality,　high　false-positive　rate,　and　unable　to　detect　unknown　anomaly.　An　industrial　control　system　intrusion　detection　method　based　on　fieldbus　network　equipment　simulation　was　proposed.　The　method　prevented　control　program　from　being　tampered　or　destroyed　based　on　controller　simulation　modelling.　Controlled　object　simulation　modelling　was　designed　for　ensuring　that　the　system　input　was　credible.　Thus　the　intrusion　detection　of　industrial　control　network　was　realized.　At　last,　the　results　indicate　that　the　proposed　intrusion　detecting　method　is　available.　©　2017,　Editorial　Board　of　Journal　on　Communications.　All　right　reserved.