Abstract: In order to study the environmental problem under high voltage transmission lines, electromagnetic field around 110 kV high voltage transmission lines were theoretically calculated and measured. Using method of simulation electric charge, we calculated electric field strength, and also computed magnetic field strength. It drew a conclusion that electric field was depended on vertical field strength, but magnetic field was depended on vertical field strength and horizontal field strength. Compared to HJ/T24-1998 where the recommendation standard of electric field is 4 kV/m and limited value of magnetic field strength is 0.1 mT, value of calculating and measure are lower national standard. Result will help paper reduce people's dread mind, who live near the high voltage transmission lines, and has realizable meaning.