Integrated modular avionics (IMA) is widely adopted by avionics industry to achieve substantial cost reduction in the development, operation and maintenance of airplanes. To meet recommended real-time and fault-tolerance requirements of IMA software architecture, the operating system (OS) should support spatial and temporal partitioning in order to integrate different applications. However, the schedulability test of partition scheduling is undetermined. We regard non-partition scheduling time as a pseudo-task with highest priority and give the schedulability test of partition scheduling based on rate monotonic (RM) algorithm. With the test, the scheduling requirement can be conducted. Through an example, the computing of scheduling parameters is proposed and three cyclic scheduling strategies at the OS level are constructed. The schedulability test can be used to validate the scheduling parameters of temporal partitioning in IMA.