Abstract: In order to meet the real-time requirements of the embedded operating system in the aerospace field, the RT-preempt patch method is adopted to optimize the real-time performance of the Linux system, and test the real-time performance of the Loongson 1E platform transplanted with the RT-preempt Linux system. The system process switching context time, interrupt response time, interrupt recovery time, and system delay are tested separately. The results show that the RT-preempt patch can meet the real-time requirements of the aerospace mission. In order to realize the reliability of the embedded operating system in the aerospace field, the exception handling mechanism of the MIPS CPU is optimized by designing an exception handling strategy for each exception. Finally, the effectiveness of the method is verified by testing typical exception handling procedures.