Abstract: A new type parallel machine tool, which utilizes a 3dof spatial parallel mechanism as main feed machanism, is proposed in this paper. The input-output equation of displacement analysis for the main feed mechanism of parallel machine tool is established. An analytical expression for determining singularity configuration which is a polynomial equation is set, and the numeric-symbolic manipulating technique is introduced in the paper. Analytical expressions of numeric-symbolic form for each coefficient of the ploynomial equation are derived. The section curve graph of a singularity surface is drawn. A numerical example of singularity configuration analysis is given for illustration.