Abstract: Accoding to the low adjustment rate and dificultadjustment of the closed loo PlD control parameters existed in the coal shearer with the electromagn:tic speed regulation thus working peromancesof the coal shearer was affcted and the stucy on the identification tfechmnology of the controlsystem paramneters was conducted. n order to high eficiently adjut the PlD control parametersof the coal sheare with the electromagneic speed regulation and to make the cal shearer with he electromagnetic speed regulation to reach the expected performance requrements of the coal shearer with elecromagnetic speed regulation at the actual operationperiod. A parameter identificatio method of the coal shearer with the elecromagneic speed regulation was provided based on the relay feedback sef-sting.The relay series fedback control was introduced and applied to the online optimization ofthe control parameters for the speed ouside loop and curent imer loop. o ugrade the parameters of the contrllr would be near the stable woark point of the system.could be completed in the operation processofth cosedloop.coud automatcally measure the constant-amplide oseliticn perod.could reduc.e the adjusted time and would not be afficed to the normal work pocess.The system could be restarted without the power off and could be favorable to the continues upgraded operation of the closed loop control system to the coal shearer with the self suitable parameters and electromagnetic speed regul.ation.The simulation and testresults approved th afrctivity of the method identfed parameter resuis and improved the ant interfrences capacity of the control system.