The test case generation method of data gathering protocol for Wireless Sensor Network (WSN) based on timed automata model was studied from the perspective of protocol testing, then the time automata model for data gathering protocol was established using UPPAAL, and the test traces set satisfied with certain coverage criteria was generated using UPPAAL CoVer. In order to facilitate the actual test case generation, an auxiliary automatic test case generation tool named Auto Test Case Generation Tool (ATCGT) was developed. The effectiveness of the method was proved by modeling and test cases generating for a wireless meter reading data gathering protocol in industry.