With more and more interrupts of integrated core processor(ICP) in avionics, VxWorks interrupt affinity which is applied to ICP has drawn substantial attention. On the multi-core programmable interrupt controller(MPIC) which is hardware platform of ICP, VxWorks interrupt affinity not only helps dispatch interrupt to specific processor core in multi-core processors but also balance the interrupt loading of multi-core processors. In this paper VxWorks affinity is applied to MPIC to achieve the purpose of shortening the interrupt response time. Firstly, the model of MPIC and its working principle have been studied in detail. And then, further research on the implementation of VxWorks interrupt affinity based on the MPIC is made. Finally, a new interrupt dynamic routing method using VxWorks interrupt affinity is proposed to enhance the performance of MPIC. The experimental results demonstrate that the method is effective in dispatching the coming interrupts across multi-core and response to interrupt more quickly.