Current methods for measuring Globoidal cam exist these problems: difficulty of measurement of profile machining error, heavy dependency on expensive measuring equipment and low measuring efficiency. In order to solve them, this paper established a high efficient virtual measuring method for globoidal cam machining errors. Based on virtual measuring theory and globoidal cam space engagement theory, and by taking the three-dimensional machining simulation models of the globoidal cam profile as the measured object, the virtual gauge head can do measurement along the planned measuring path. The machining error calculation method was determined according to the degree of geometric interference between virtual gauge head and the surface of machined models. And a virtual measuring system on UG platform for globoidal cam profile machining errors was built by use of Visual C++ 6.0 and UG/Open API secondary development tools. Finally, a virtual measuring experiment was performed for the two kind of machining simulation models generated by generating method and one-side machining method. The experimental results show that the high efficient virtual measuring method for globoidal cam machining error is correct and the virtual measuring system is reliable. On the one hand, an effective method is provided to achieve an efficient, low-cost measurement for globoidal cam profile machining errors in this paper. On the other hand, it has great engineering guiding significance for the actual production and processing of globoidal cam.