Abstract:The uniform representation of the potential function and power line function in the system of an finite line charge is obtained. In real life and production mankind physically comes in contact with electric conductor is impossibly infinite long. Being limited long, as long as the length of electric conductor to be far larger than its width, it can be simplified in limited length of the line electric charge model being carried on a research. As a result, the textual research has important theories meaning and physically applies value. There are a few teaching materials and reference materials in study of the equipotential lines and power lines in the system of a finite linecharge. According to the characteristics that the equipotential line and the power line are orthogonal each other. By means of combination of integral-transform method and software package facility of Mathematics 5.0, we have obtained the exact solution of electrical potential functions and power line functions in the system of an finite line charge and plotted the relative equipotential line maps and power line maps. Meanwhile, we have made the necessary discussions.