Using aircraft maintenance manual (AMM) and fault isolation manual (FIM), this paper clearly illustrates the system principle of thrust reverser as an example of 737NG aircraft. Combining common fault phenomena and possible causes of faults in thrust reverser system, the fault tree theory is used to establish a set of rapid identification, judgment and elimination methods for different fault phenomena. It will help civil aviation maintenance personnel to master the principle of thrust reverser, accurately determine faults, and ensure the aircraft operating normally. At the same time, it will contribute to aircraft design, manufacturing, and maintenance plan formulation.