The invention discloses a technique for preventing nano silver soldering paste on the basis of a reversed-phase microemulsion system. The technique comprises the following steps of (1) preparing a mixed silver nitrate aqueous solution; (2) preparing a hydrazine hydrate solution; (3) preparing polymer electrolyte aqueous solution reversed-phase microemulsion and drawing a pseudo-ternary phase diagram; (4) preparing the nano silver soldering paste; and (5) adjusting the viscosity of the soldering paste of the system, and interconnecting the soldering paste to a DBC substrate and an IGBT power chip module. By adopting the technical scheme, the technique has the beneficial effects that the technique is simple to operate, formation of an optimal reversed-phase microemulsion system can be judged conveniently, and the problems that the reversed-phase microemulsion system is poor in stability and nanoparticles are easily agglomerated are solved.