This　paper　predicts　the　effect　of　main　parameters　to　the　failure　behavior　of　T300/AG80　composite　plate　under　preload　and　laser　irradiation　by　experimental　testing　and　data　fitting.　The　load　holding　device　was　used　to　give　certain　preload　to　composite　plate　specimens,　and　an　Nd:　YAG　laser　was　used　to　give　laser　radiation　simultaneously　for　testing　the　failure　time　of　the　specimens.　By　varying　the　magnitudes　of　preload　and　the　laser　power　densities,　the　effect　of　preload　and　laser　power　density　on　the　failure　time　is　obtained.　The　reaction　process　was　recorded　with　a　high-speed　camera.　The　experimental　data　were　fitted　to　obtain　the　expression　of　the　materials　failure　time　with　preload　and　laser　power　density.　When　the　preload　kept　constant,　the　relationship　between　the　failure　time　and　laser　power　density　was　exponential　function.　When　the　laser　power　density　kept　constant,　the　relationship　between　the　failure　time　and　pre-tensile-loads　was　approximating　linear,　and　pre-compress-load　was　quadratic.　Fitting　the　empirical　formula　provides　a　reference　to　predict　life　for　the　composite　structure　applied　both　preload　and　the　action　of　the　laser　irradiation.　©　(2012)　Trans　Tech　Publications,　Switzerland.