An encryption algorithm based on an electric power emergency communication system is used for ensuring safe and efficient transmission of data information in the electric power emergency communicationsystem. According to the technical scheme, the method comprises the steps that firstly, chaotic mapping is utilized for generating two random number sequences R and Q, an r confusion matrix and a q confusion matrix corresponding to the two random number sequences R and Q are constructed, and then plaintext is encrypted according to the following steps that A, XOR operation is conducted on the plaintext and an initial secret key; B, carrying out scrambling operation; C, combination operation; D, column mixing; E, diagonal interchange; F, generating a next round of secret key; and G, generatinga final ciphertext. According to the method, the secret key generated by chaotic mapping is utilized, the encryption algorithm of scrambling, combination operation, column confusion and diagonal interchange is combined to generate the ciphertext, the good encryption effect is achieved, the anti-attack performance and the good anti-tamper performance are achieved, the data transmission rate is increased, and the requirements for safety and real-time performance of information transmission can be met at the same time.