RSA is one of the well-known public key cryptography algorithms (asymmetric encryption cryptosystem) , it has been more than 40 years since it was put forward. There are countless literatures on RSA related issues; hot discussion and popularization in academic and industrial circles, it is one of the typical public key cryptosystems. The reliability of RSA algorithm mainly depends on the factorization of large integers mentioned in the principle of RSA algorithm because it is extremely difficult to factorize very large integers. Unfortunately, there is no sufficient way to break the RSA. Due to the low efficiency and decryption speed of RSA computing, many scholars are committed to improving the efficiency of RSA algorithm, Ping Li and Yong Li’s algorithm (hereinafter referred to as Li-Li algorithm) is one of the research literature. A hybrid encryption algorithm based on XOR operation proposed by Li-Li has defects, this defect is not easy to detect, this paper will point out the problem and give examples to prove the authors claims.