Abstract: Based on the welding inspection results of test pipe sections in Sebei-Xi'ning-Lanzhou gas pipeline, the experiment and analysis on the conventional mechanics characteristics of weld metal for X70 pipe steel are carried out. During the sample experiment of weld metal, the pinhole in notch in tensile test, the brittle fracture in bending test and high discreteness of Sharpy V test are found. The macro and micro analysis on the experiment results are made.