In recent years，the academic community has been concerned about the existence of “legislative duplication” in local legislation. To verify the extent of this concern，it is necessary to calculate the repetition rate of local laws and regulations scientifically，but at present，the academic community has not yet clearly unified and reasonable evaluation criteria. In fact，the essence of the problem of legislative repetition is the conflict of the dual values of the consistency and characteristics of local legislation，which is the place that can not be ignored in the construction of scientific evaluation standards. Based on the principle of balancing the dual values，this paper tries to put forward the evaluation criteria of repeated legislation of local laws and regulations，and on this basis，analyzes the text of 17 provincial local laws and regulations on city appearance and environmental sanitation. The analysis results show that 17 laws and regulations have the problems of high repetition rate，poor innovation and insufficient local characteristics. The reason lies in the imbalance of the dual value of local legislation. Therefore，in order to solve the problem of high repetition rate of local legislation，it is necessary to adhere to the balance of dual value when optimizing the structure，content and working mechanism of local laws and regulations，improve the quality of local legislation and give full play to the characteristics of local legislation.