In view of principle and structure of missile-borne laser detector, combined with its service environment and specific characteristic, FMEA method was used to analyze the laser detector's potential failure mode, failure consequences, and its failure reason or mechanism such as high overload, sealing and pollution, etc, up to six common potential failure modes were discussed. Strategies such as derating design, increasing screening, optimizing structure and process, device reinforcement and other precautions were proposed for analysis and improvement of the laser detector's stability and reliability, providing design and production process control of the ideas and reference.