Low alloy steel 16MND5 for pressure vessel of domestic nuclear power reactor type "HPR1000" reactor has been developed domestically with manual welding electrode. Electrode welding process has long relied on the experience of welding workers, and it is difficult to scientifically and quantitatively determine the advantages and disadvantages of electrode welding process performance. Through the research on the quantitative evaluation method of process performance index, the comparison and quantitative evaluation of process performance between newly developed domestic electrodes and imported welding materials are carried out, and the factors affecting the stability of welding process are summarized and studied, such as arc stability For slag removal and forming appearance, the process performance indexes of welding materials are scientifically evaluated by quantitative method. From the evaluation results, the existing quantitative evaluation standards and methods of process performance can scientifically evaluate the welding process performance of welding electrodes. Compared with the evaluation results, the process performance of domestic manual welding electrodes is equivalent to that of imported welding materials, reaching the research goal of the subject project. Through quantitative evaluation, it is proved that domestic welding materials have realized the transformation from "usable" to "easy to use".