The invention discloses a road network matching method facing a lightweight terminal. The method includes: 1) indicating each road R in a road network Map as a safety projection area (SPAR) and storing communication relation between the roads to obtain a road network simplified model (SPA-Map) and install the model on the lightweight terminal; 2) building a safety projection area grid (SPA-Grid) indexing the rod network simplified model and with the indexing object as the SPAR and installing the grid on the lightweight terminal; 3) enabling the lightweight terminal to search a safety projection area (SPA) set capable of being projected according to the SPA-Grid for a global position system (GPS) point P and returning road information of the p point. Compared with the prior art, the road network matching method greatly reduces road network data storage scale on the premise that road network matching accuracy is slightly reduced and enables road network matching on the lightweight terminal with limited internal memory and calculation capability to be possible.