针对风云三号（FY-3）卫星在轨寿命从3年延长到5年的特点，分析了寿命延长存在的风险，并对微波成像仪可靠性关键项目的扫描驱动系统和接收机系统的可靠度作了预估，同时从设计上采取相应措施，并作了一些提高可靠性的工艺改进。通过具体的分析与产品的改进，能够为微波成像仪在轨正常运行提供稳定有效的保障。最后，为了证明产品延寿技术的可靠性，提出了进行加速寿命试验的设想。

Considering the characteristics of Fengyun-3(FY-3) satellite lifespan on orbit increased from 3 years to 5 years, the risk of extending lifespan was analyzed, and the reliability of scan driver system and receiver system which were critical items of microwave radiation imager was evaluated, taking corresponding measures from design and improving crafts reliability. Microwave radiation imager operates normally on orbit and provides effective reliability assurance according to these methods. Finally, the ideal of accelerated lifespan test was put forward at last.