To address the problem of low kappa, precision and recall values, and high misjudgment rate in traditional methods, this study proposes an English grammatical error identification method based on a machine translation model. For this purpose, a bidirectional long short-term memory (Bi-LSTM) model is established to diagnose English grammatical errors. A machine learning (ML) model, i.e., Naive Bayes is used for the result classification of the English grammatical error diagnosis, and the N-gram model is utilized to effectively point out the location of the error. According to the preprocessing results, a grammatical error generation model is designed, a parallel corpus is built from which a training dataset for the model training is generated, and different types of grammatical errors are also checked. The overall architecture of the machine translation model is given, and the model parameters are trained on a large-scale modification of the wrong learner corpus, which greatly improves the accuracy of grammatical error identification. The experimental outcomes reveal that the model used in this study significantly improves the kappa value, the precision and recall values, and the misjudgment rate remains below 1.0, which clearly demonstrates that the detection effect is superior.