目的 针对一种六自由度3-PUPU并联机构，对其运动性能和工作空间进行研究。方法 利用修正的(G-K)公式对该并联机构动平台的自由度进行计算，并建立机构的逆运动学和正运动学特征方程式，然后利用Matlab/Simulink中的SimMechanics功能模块建立3-PUPU并联机构及结构框图，利用杆长的运动范围限制条件编程求得3-PUPU并联机构的工作空间。结果 该并联机构的工作空间范围较大，形状规则，结构紧凑，无空洞。结论 3-PUPU机构具有良好的工作空间性能。

The paper aims to research motion performance and workspace of a six DOF 3-PUPU parallel mechanism. The freedom degree of the moving platform of the parallel mechanism was calculated by using the modified (G-K) formula. And the kinematics and inverse kinematics equation of mechanism was established. Then the 3-PUPU parallel mechanism and structure block diagram were established by using the SimMechanics function module of Matlab/Simu- link; and the workspace of the 3-PUPU parallel mechanism was obtained by programming according to restriction condition of rod length. The workspace of the parallel mechanism had large range, regular shape, compact structure and is free from holes. 3-PUPU parallel mechanism has good performance of workspace.