In order to Predicting residual life of metal pipe of uniform corrosion. Field signature method is a new measurement method through potential matrix. It can detect metal loss, cracks and potholes caused by corrosion through subtle changes of current on the metal structure. Its detection accuracy is relatively high, and sensitivity is 1% of wall thickness of metal pipe. It can also calculate the corrosion rate of the pipeline. We tested wall thickness of a metal pipe with 720 mm diameter and 10mm thickness. We selected 15 different position. And we test it every 3 months. We calculated the metal pipe wall thickness through the change of the voltage between electrodes. Corrosion rate is related to many factors, such as time, oxygen content, materials of pipe, etc. This paper analyzes the defects of the method that API579 predict the residual life of metal pipes Subjected to uniform corrosion. We have detected metal pipe corrosion through field signature method. Finally, we exploratory put forward the mathematical model for predicting the remaining life of the pipeline Subjected to uniform corrosion. And we add the Impact factor K in the mathematical model.