Automated code generation has revolutionized software development, enabling developers to accelerate project timelines and reduce manual coding errors significantly. As reliance on these technologies grows, the inherent weaknesses of generated code become increasingly apparent. Recent studies have shown that code produced by AI is not inherently safer or of higher quality than human-written code, often replicating existing vulnerabilities.To this end, we propose SECURECODER, which integrates Retrieval-Augmented Generation (RAG) with Common Weakness Enumeration (CWE). SECURECODER first utilizes the advanced reasoning capabilities of large language models (LLMs) to generate natural language descriptions of the code’s core business logic and functionality. Then, from a semantic perspective, it matches the requirements of the code generation task with the CWE descriptions through a multi-label classification process. Finally, based on the matched CWE, SECURECODER generates a list of security guidelines the code generation model must adhere to. Breaking down end-to-end code generation tasks into single-target tasks that LLMs excel at ensures that the generated code not only meets functional requirements but also adheres to best security practices, thereby enhancing the interpretability of the automated code generation process. After evaluating 2 programming languages and 7 LLMs on Coploit-generated code, SECURECODER has great generalization capability and could be applied to more programming languages and vulnerability types. SECURECODER could significantly decrease the security weakness in the AI-generated code and is able to mitigate more than 65% of vulnerabilities exposed to software developers. Compared to the baseline open-source LLMs, code vulnerabilities were reduced by at least 14% and the code business logic was not affected.