With the progress of The times and the development of seienee and technology ,the effeet of magneticield on plasma has important applications in many fields, such as magnetie confinement fusion, plasmahrusters , plasma etching and so on.'These applications are based on the control and confinement of the chargedpartieles of the plasma by the magnetie field,and the precise control of the plasma is achieved by adjusting thentensity and distribution of the magnetie field.The eflect of magnetie field on the illuminanee of plasma is aomplicated and interesting problem.lt involves many aspeets such as the restraint and guiding elfect ofnagnetie field on plasma motion ,the special physical effeets such as magnetie botle efeet and the infuenee olnagnelie field intensity on the luminescence characteristies of plasma.Therefore , when studying the influenee ofnagnetie field on plasma illuminanee ,it is necessary to consider these factors comprehensively ,and carry outn-depth experimental and theoretieal analysis.By changing the exeitation current to control the magnetic fieldize and measure the luminous intensity of neon lamp tube,A new type of magnetie field feedbaek alarm deviees made ,and code is written to test the alarm device so as to achieve the purpose of feedback the magnetie fieldhrough the light intensity.The method is through software data processing to assist the experiment to draw aonclusion ,and according to the conelusion ,the magnetie field feedback alarm device is made.