针对投影测长机这一高精度的测量设备 ,论述了影响其测量准确度的主要因素 ,并运用全面质量管理方法中的因果图和对策表 ,从多方面进行原因分析 ,提出相应的解决办法 Aiming at the high accuracy measurement equipment of projection length measuring machine, the main factors affecting its measurement accuracy are discussed. The cause and effect diagram and countermeasure table of total quality management method are used to analyze the causes from many aspects and put forward the corresponding solutions