The resistance spot welding of 1.3 mm-thick GH3536 nickel-based superalloy sheets was performed via DZ-X100 three-phase secondary rectifier spot welding machine with spherical electrodes made of BeCoCu-alloy, aiming to simulate the actual operating conditions in a production line, and to examine the applicability of the electrodes and their failure process after long term service. The results show that the useable number of times of the BeCoCu-alloy electrodes is approximately 220 times for spot welding. When the electrode fails, it can be observed that on the electrode end surface, metals-accumulation and -adhesion occur, the grains size increases, and pits appear due to erosion. These may be ascribed to that during welding, elements such as Fe, Ni, Cr etc. in the superalloy may diffuse inwards the electrode to form (Fe, Ni) substitution solid solution, as well as brittle intermetallic compounds such as Fe_0.7Cr_0.19Ni_1.1, Cr_0.19Fe_0.7Ni_0.11 and Cu_0.81Ni_0.19. Such alloying process may cause microcracks on the electrode surface, which is conductive to the occurrence of failure and spallation. The failure process involves the transformation of the alloy texture from stronger cubic {100}<001> and {110}<100> textures to weaker cubic<111>||ND texture, resulting in reduction of its relative strength from 4.12 and 5.62 to 3.05. Additionally, during the service process of BeCoCu electrode, the amount of high-angle grain boundary increases, which promotes alloying process of the electrode. These factors together lead to electrode failure.