This paper proposed an improved March CS algorithm to complete the built-in self-test of SRAM memory due to the problem of March C + algorithm's fault coverage. The static and dynamic fault of memory cell were sensitized by the original algorithm increasing the read-write operation of the algorithm element， so that the fault coverage was enhanced. Finally， the March CS algorithm achievesd 91.67% and 76.93% coverage of static and dynamic faults respectively through the simulation experiments of the 1 024*32-size fault static Randon-Access memory and the measurement of FPGA to SRAM chips.