The evaluation of engineering geological environment along Shenzen-Dayawan coastal highway was quicly completed by Landsat TM digital image interpretation for geo-science ioformation study using computer information enhance and extracting techniques combining aerial photo stereoscopy and field investigating and verifying. TM theme ioformation image processed by computer using different methods has played an important part in geological structure interpretation and rock and soil mass classify. Aerial photo is usfull in geological body boundary demarcating and geological hazard phenomenon analysis. The complete work including image processing and interpretation, field check and mapping as well as report compiling had accomplished in less than two months. It is saving exploration fund more than 50%, meeting the requirement of earlier stage before road exploration, and fully reflecting the advantage of remote sensing technology. Remote sensing combining conventional method of geological field check and mapping is a state-of-the-art toal for road exploration and can get twice the result with half the effort.