Abstract: With the development of integrated modular avionics, partition management has become a necessary technology. To solve the partition management problem under safety critical system constraint, through studying ARINC653 criterion, hierarchical partition architecture model was determined which implement partitioning between applications of different safety critical levels. To guarantee timing constraints and predictability of avionics, a two-level partition schedule model was proposed in which the operation system adopts round-robin scheduling strategy and each individual partition adopts rate monotonic priority scheduling strategy. In addition, for the schedulable analysis problem of partition tasks, on the premise that fully guarantee real time characteristics of integrated modular avionics systems, a design method for partition critical parameters was developed. The least upper bounds of the system schedulable utilization for the method was derived and formally proved. Computer simulation results indicate this approach can be used to admit much more systems load, while guarantee real time properties.