In order to study the security of the Midori128 cryptographic algorithm against integral fault attack, the relationship between integral distinguisher balance position, fault ciphertext, and the round key was established, and the last round key of the algorithm could be recovered by key search, and then the master key could be recovered by using key extension algorithm. The theoretical analysis shows that the time complexity of recovering the correct key is 2²¹ and 2²⁴ when using 3 and 4 rounds of integral distinguisher for the integral fault attack, respectively. The accuracy, success rate, and elapsed time were used to simulate the attack process of the fourth round of injection fault, and the master key of the algorithm was successfully recovered. Comparison experiments were conducted for different plaintext groups and keys. The two sets of fault security analysis schemes conclude that the round function of the Midori128 algorithm is vulnerable to integral fault attacks and requires additional protection such as fault detection for at least the last 6 rounds while the algorithm is running.