This article is devoted to investigation of the resistance spot welding of Fe-Ni-Co alloy and Cu wires by the method of analog modeling. Welding is a complicated object to research: integrated investigation and description of characteristics of welding by existing mathematical methods not achieved at this time. The application of system analyses by logical functions allows to describe the causal and effect relationships between large number of parameters of the technological process. For the logically verified original solution development, the analog model of resistance welding of Fe-Ni-Co alloy and Cu wires was elaborated. On the basis of this model the summarized solution, that provides the welding joints of high quality, was developed. The technological parameters were optimized by the method of complex planning of experiment