Aim\ To research each step and algorithm in STL model pre processing of LLS RP system. Methods\ Structual analysis are used to finish the algorithms in STL model pre processing of the distinctive LLS RP system. Results\ The algorithms are robust
efficient and adaptable through the application examination. Conclusion\ STL model pre processing is an important procedure in the practical application of RP technology
the advised algorithms can well meet the needs of LLS RP system.