To solve the problems of network information security caused by the rapid development of the Internet, predecessors proposed an image information hiding technology based on the least significant bit algorithm. This method cleverly uses the redundant attributes of media information to hide secret information in other media information, obtaining a carrier embedded with secrets that can be publicly disseminated. The information can be stored and transmitted because lawless people cannot detect the hidden data. Previously, the concealed information is limited as only the lowest digit of secret information is hidden. To solve this, we embed every two consecutive digits of the secret information in two of the least four digits of every byte in the carrier image on the principle of “matching first and making replacement if it fails”. In this way, the hidden amount of the traditional least significant bit algorithm is increased. The results show that the algorithm can meet the needs of users for information hiding due to its large hidden amount, little reduction in image quality after hiding, high safety, and ability to correctly extract secret information.