This research is based on spark ignition（SI）engine combustion test bench

in which

the ignition advance angle of the engine be changed to get high knock intensity load cases.10° and 20° crank angle before and after low-pass combustion pressure peak value was selected as knock sensitive window（KSW）.ARMA time serial model was chosen to simulate high-frequency vibration signal of a bench of KSW.Mahalanobis distance of vector

created by mean value of ARMA model’s parametric

was selected to indentify knock phenomenon.Threshold value

designed by Monte-Carlo approach on mahalanobis distance of non-engine knock cycles

is suitable to indentify knock case

and was tested by experiment data from SI engine combustion test.The feasibility of this method was verified by VDO method

which was widely used in engineering.