A grinding/electrolysis combined multi-wire-slicing processing method for silicon wafers includes the following steps: first, with a metal slicing wire (10) provided on a multi-wire-slicing machine serving as cathode, a silicon rod or a silicon ingot (1) (anode) is processed by grinding/electrolysis combined multi-wire-slicing through application of a voltage; second, during said processing, the metal slicing wire (10) and the silicon rod or a silicon ingot (1) are connected with a low-voltage continuous or pulsed direct current power supply (9); third, an electrolytic liquid is sprayed into the cutting area to ensure cooling and anode erosion. The method reduces macroscopic cutting force and enables a grinding/electrolysis combined multi-wire-slicing processing method for large size ultra-thin silicon wafers.