Coordinate measuring machine (CMM) is a large-scale geometrical detecting instrument. It is of high accuracy, high efficiency simple operation and automation. So, it can ensure the product quality for modern mechanical manufacture industry, and is widely used in the industry such as aircraft, automobile, military and national defense. However, it does not meet gradually the requirement of modern industry because of its measuring accuracy. How to monitor geometrical error rapidly and high accurately is a key research project. To solve the problem, some studies have been carried out. In this paper, a coordinate measuring machine was firstly designed by modern design method. Three dimensional model is built using PRO/E software. And some key components were optimized by using finite element analysis method. The simulating results show that the size and structure of the designed coordinate measuring machines are optimized and improved relate to previous CMM. This study will play an important instructing role for us in studying a novel CMM.