With the increase of complexity of modern embedded system software,it becomes more difficult to discover and handle all potential software faults.Practical application has shown that there are still some software runtime errors that cannot be discovered by conventional test method.A method was proposed by introducing software health management into the design of embedded system software,to improve the reliability of embedded system software.This method was realized by constructing runtime error monitoring,diagnosis and recovery models in the embedded system software.To verify its effectiveness,taking software errors occurred in 2005 in airborne ADIRU of Malaysian Air Flight 124 as an example,a software model was established for ADIRU by using AADL language,and the effectiveness of software health management was proved through this model.