Parallel robot is used in many different fields nowadays,but the singularity of 3-RRUR parallel robot is more complicated,so a method to analyze the singularity of the 3-RRUR parallel robot is very necessary.First,the Jacobian matrix was built based on the differential transform method through the transfer matrixes between the poles.The connection between the position parameters and singularity condition was built through the analysis of the Jacobian matrix.Second,the effect on the singularity from the position parameters was analyzed,and then the singularity condition was confirmed.The effect on the singularity condition from position parameters was displayed by the curved surface charts to provide a basic method for the designing of the parallel robot.With this method,the singularity condition could be got when the length of each link is firmed,so it can be judged that if a group of parameters are appropriate or not,and the method also provides warrant for workspace and path planning of the parallel robot. Parallel robot is used in many different fields nowadays, but the singularity of 3-RRUR parallel robot is more complicated, so a method to analyze the singularity of the 3-RRUR parallel robot is very necessary. First, the Jacobian matrix was built on the differential transform method through the transfer matrixes between the poles. the connection between the position parameters and singularity condition was built through the analysis of the Jacobian matrix. Second, the effect on the singularity from the position parameters was analyzed, and then the singularity condition was confirmed that the effect on the singularity condition from position parameters was displayed by the curved surface charts to provide a basic method for the designing of the parallel robot. This way the singularity condition could be got when the length of each link is firmed , so it can be judged that if a group of parameters is appropriate or not, and the method also provides warrant for workspace and path planning of the parallel robot.