The　multi-transient　electromagnetic　(MTEM)　method　can　achieve　good　anti-noise　performance　with　transmitted　waveform　coded　by　m-sequence.However,m-sequences　with　different　coding　parameters　have　different　anti-noise　performance.First,we　reveal　significant　differences　in　the　identification　precision　of　different　coding　parameters.Then　we　build　an　identification　system　by　constructing　a　model　of　the　identification　progress.For　the　identification　system,the　input　is　an　impulse　to　the　earth,and　the　output　is　the　response　of　the　impulse.The　noise　attenuation　at　a　specific　frequency　can　be　quantitatively　analyzed　by　the　amplitude-frequency　response　of　the　identification　system.Based　on　this　method,effects　of　coding　parameters　on　the　anti-noise　performance　are　summarized　by　numerical　simulation　and　the　coding　parameter　optimization　is　further　discussed　and　concluded.Field　experiments　demonstrate　the　validity　of　the　proposed　method　and　coding　parameter　optimization　conclusions.　©　2018,　Editorial　Department　OIL　GEOPHYSICAL　PROSPECTING.　All　right　reserved.