Abstract: A high dimensional stable composite truss used for a certain satellite is discussed in this paper. Through the material selection, the ply design, and the CTE test & analysis, a high precision composite truss is manufactured, and the thermal deformation of the truss is measured. It is shown that the high dimensional stable structure made of high modulus CFRP with micrometer level accuracy can be obtained through an appropriate ply design. Some suggestions are made for reducing the thermal deformation and improving the dimensional stability & measurement accuracy. It is the first successful practice of the high dimensional stable composite structure being used for the ultra-stable satellite platform.