Abstract: At present,in the new situation of smart grid development,higher requirements are put forward for the stability of power system. The deficiency of traditional microcomputer relay protection is analyzed. A dynamic time warping is used as the protection algorithm of the device,it develops a microcomputer relay protection device based on DSP and ARM dual processor. Taking the transformer main protection for example,test results show that the performance of the hardware platform system can completely meet the demand of the development of modern power grid.