In this study, the effects of laser parameter modulation, polyimide (PI) chemical pretreatment and metal sputtering on the electrical resistance characteristics and surface morphology of LIG were systematically investigated for the optimisation of laser-induced graphene (LIG) conductivity. The experimental results show that the resistance value of LIG is significantly negatively correlated with the laser energy density in the energy density range of 10.87~46.25 J/mm2, and the resistance value of the LIG obtained from the pretreatment of the PI substrate with 2 mol/L NaOH and 0.0282 mol/L AgNO3 solution is reduced by two orders of magnitude compared with that of the original sample, which is superior to the performance of the other comparative solutions; Further sputtering of a platinum (Pt) metal layer on the surface of the pretreated sample can reduce the resistance value by a maximum of 15.07%. This study provides an effective process optimisation strategy for the preparation of high-performance LIGs.