To solve the problems that subjective factor is major in test result of test system of aeroengine and the life of aeroengine is wasted because of the slow test seed, an automatic test system is designed. Firstly, the whole project is introduced, the hardware structure of automatic test system is analyzed and the measure circuits such as the high and low pressure rotating speed signals, weak signals T1, T3, T6, etc. are designed. Next, the software flow is analyzed. For the purpose of realizing the determination of test points in the search process, a seek-self searching algorithm in time order is put forward in combination with single factor test method 0.618, the structure and flow of the algorithm are analyzed and the fundamental of the algorithm is illuminated. Finally, the test system is tested using an aeroengine. The test result shows that the design of the hardware structure of the test system is reasonable and logical, the signal collected is accurate, the error is content with the requirement, the design of the software flow is logical, the searching algorithm is fast, accurate and the measure speed is doubled which will save the service life of aeroengine.