In this paper, a new experimental teaching design of electromagnetic wave is proposed, in which the mobile phone is transformed into a microwave power meter and Wi-Fi router is used as the transmitting signal source. The experiment is used to study the electromagnetic wave propagation characteristics, electromagnetic wave polarization characteristics and electromagnetic shielding efficiency. The experimental equipment is popular, easy to operate, and the time and location of the experiment are not limited, which can meet the diversified learning needs of students in the Internet era. In addition, the experimental design is combined with life practice and encourages free play, which plays a positive role in promoting learning interest and cultivating innovative thinking.