Dynamic encryption and decryption method among lock control system modules comprise the following steps: step 1. filling hardware ID data, an unlocking communication protocol and a mask variable into an array according to a predefined variable space, and encrypting the array based on the mask variable to obtain an encrypted array; step 2. decrypting the encrypted array based on the mask variable to obtain a decrypted array, executing data division on the decrypted array according to the predefined variable space, matching the divided data with data recorded in advance one by one, and if the divided data are consistent with the data recorded in advance, executing related operations according to the decrypted unlocking communication protocol content; otherwise, executing no operation.