By analyzing the working principle and technical feature of the detection technology for the external corrosion of buried pipeline, including pearson, pipe current mapping, direct current voltage gradient and close interval potential survey,the feasibility of the external corrosion detection of buried vessel by these methods was analyzed. Meanwhile, several on-line external corrosion monitoring technologies of soil corrosion were introduced, such as electrical resistance probe method, inductance probe method, field signal method, coupling electrode corrosion monitoring, etc. which offered theory reference for doing correlative work.