The essence and complicacy of approach to computer design of an optimal pulsed arc welding technology is that programmed periodic action should be developed on the one hand to exert its effect on melting and transfer of an electrode metal, and on the other hand, to control over the molten pool fluidity, the structural formation of weld and heat-affected zone that appears as result of the weld pool crystallization whilst ensuring stability of the pulsed regime in welding in different spatial positions. The results of physical simulation and mathematical modelling permit to design optimal algorithms of pulsed control of energy characteristics of welding-arc current and voltage, arc heated efficiency, peak short-circuiting current. The results of computer experiments permit to establish pulsed welding controlled parameters-service properties of welded joints (such as the sizes of welds and heat-affected zone, quality and strength properties of welded joints) relation.