This paper introduces the structure and operating principle of double eccentric mechanism used in a special environment to realize the two-dimension precision adjustment, establishes its precise mathematic model, analyzes the theory model with simulation model, and researches it by test. All of which indicate that the operating principle and mathematic model of double eccentric two-dimension precision adjustment mechanism are right. Under the condition of some processing and control accuracy, the adjusting error can satisfy the requirement. Through analyzing on the test data, it shows the circular degree and eccentric errors are the main sources of adjusting errors.