We carried out a research on the precision of femtosecond laser induced silver nanowiring and its application in micro-device integration. The precision of the silver nanowires could be controlled by the laser power, exposure duration, surfactant type and their concentrations in the precursor solution. An experiment of interaction between femtosecond laser and Ag precursor solution was conducted. Experimental results show that silver nanowires with high precision (140 nm) could be prepared, which was confirmed by means of scanning electron microscope. Meanwhile, a micro-pattern of silver nanowires and a micro-catalytic-reactor were produced by femtosecond laser direct writing technique. The research may open up a new way to the designable patterning of silver microstructures toward flexible fabrication and integration of silver functional devices.