Language learning has increasingly benefited from Computer-Assisted Language Learning (CALL) technologies, especially with Artificial Intelligence involved in recent years. CALL in writing learning acknowledged as the core of language learning is being realized by technologies like Automated Writing Evaluation (AWE), and Automated Essay Scoring (AES), which have developed considerably in both computer and language education fields. AWE has effectively enhanced EFL students' writing performance to some extent, but such technology can only provide an evaluation in the form of scores, the majority of which are based on holistic scoring, resulting in the inability to provide comprehensive and detailed content-based feedback. In order to provide not only the writing multiple trait-specific evaluation scores, but also detailed writing feedback, we proposed a computer-assisted EFL writing learning system incorporating the neural network models and a couple of semantic-based NLP techniques, MsCAEWL, which fully meets the requirements of writing feedback theory, i.e., multiple, continuous, timely, clear, and multi-aspect guidance interactive feedback. The results of comparison experiments with the AWE baseline models and human raters demonstrated the superiority and the high correlation contained by the proposed system. The independent-sample t-test and paired-sample t-test results of the experiments on MsCAEWL effect validation suggested the significant impact of our proposed system in enhancing students' EFL writing proficiency.