Based on equal runlength code and IFDR, a new coding method (called ERFDR) was proposed.Firstly, the proposed method can not only encode both 0 and 1 runs for a test set simultaneously, but also can use shorter code if the adjacent runlengths are equal.Therefore, the compression ratio can be further improved.This paper also put forward a new filling algorithm for a test set with don't care bits, which can enhance the compression efficiency of the proposed method.Experimental results show that the proposed method can obtain a higher compression rate compared with FDR, EFDR, IFDR and ERLC codes.The test cost can be reduced effectively.