To estimate the future development of one technology and make decisions whether to invest in it or not, one needs to know the stage status of its technology life cycle (TLC). The major approach to analysing TLC uses the S-curve to observe patent applications over time. But using the patent application counts alone to represent the development of technology oversimplifies the situation. In this paper, we build a model to calculate the TLC for an object technology based on multiple patent-related indicators. The model includes the following steps: first, we focus on devising and assessing patent-based TLC indicators. Then we choose some technologies (training technologies) with identified life cycle stages, and finally compare the indicator features in training technologies with the indicator values in an object technology (test technology) by Nearest Neighbour Classifier, which is widely used in Pattern Recognition, to measure the technology life cycle stages of the object technology. The method and result of this study can be used in management practice to enable technology observers to determine the current life cycle stage of a particular technology of interest.