Abstract: With rapid development of 5G communication technology and wide application of micro meteorological online monitoring equipment,it is common for 5G equipment and micro meteorological online monitoring equipment to use the same tower. With this arrangement,the 5G antenna may cause certain electromagnetic interference to the normal operation of online monitoring equipment. Therefore, according to the working principle of 5G base station antenna, this paper analyzes the interference mechanism of 5G base station antenna on the micro meteorological online monitoring equipment in the context of the common tower, obtains the field source characterization formula of 5G antenna based on the principle of array antenna, and establishes the mathematical model of electromagnetic interference. Finally,an actual shared tower is taken as an example for simulation calculation,the results show that the surface field strength of the micro meteorological online monitoring equipment increases with the increase of the number of antennas and power,and decreases with the increase of the antenna tilt angle.