Power system is tending to form a large scale network with numerous interconnected subsystems. In order to maintain the reliability and stability of the power grid, multiple analysis systems with specific hardware platforms are implemented in the electrical power dispatching centre, which makes the software maintenance and hardware management more complicated and ponderous. This paper describes a common task based parallel platform for power system analysis and stability assessment, in which multiple analysis systems and applications can be implemented respectively by sharing the same hardware and support software. The computers in the platform are assigned as data server, computation workstations or console workstations. There are two roles for the computation workstations, one is assumed the manager, and the others are assumed the node. The support software includes 9 programs: file transfer service, configuration service, database service, raw data service, task partitioning interface, task dispatching service, calculation interface, result processing interface and computation management service. Analysis systems and applications can easily be integrated into the platform by development of 3 programs: the task partitioning program, the calculation program and the result processing program. The parallel platform is designed to meet the needs of different applications, by which the hardware costs are reduced and the development cycle is shortened. It is also beneficial to enhance the reliability of power system operations.