The surface material quality of electronic components was the key factor influencing surface binding force between electromagnetic shielding coatings and packaging materials. The work aims to improve the surface quality of electronic package by putting forward a novel surface technology-dry ice treatment technology, which can be applied to high precision electronic processing field. The influencing rule of such key parameters as injection pressure, injection angle and clean speed on surface impurity removal of electronic materials was studied in depth based on experimental design. Function mechanism of treating surface of packaging materials by dry ice was analyzed, and quality of electromagnetic shielding films acquired by using dry ice and traditional deionized water was compared. As a result, the function mechanism was like this: the impact force produced by physical impact and micro explosion peeled off and removed impurities adhering to side wall. Under the optimum reaction conditions obtained from the experiment: injection pressure of 0.2~0.4 MPa, action speed of 40~50 mm/s and injection angle of 40?~70?, surface quality of the potted element PCB side wall improved significantly, copper impurity content of the surface PCB area reduced from 30% to 2%, breakage rate of the solder mask was controlled, binding force level of the electromagnetic shielding coating was improved effectively. Since the whole process of dry clean is efficient, easy to operate and free from side effects provided with optimum process parameters, it can provide technical support for surface treatment in future manufacturing of electronic components.