Objective: Pediatric dosages are primarily mg/kg-based. However, currently, patient records lack complete weight information, the alert system does not differentiate between pediatric and adult patients, and the drug database lacks pediatric maximum dosage data. Methods: Using a quality control circle problem-solving approach, we identified three root causes: dose checking logic not applicable to the paediatric population, not mandatory input of height and weight, and lack of paediatric limit settings in the drug master file. Subsequently, we formulated countermeasures. Results: The number of overdosage exceptions in children was 2 before improvement, and the target was reduced to 0 and 1 after improvement. Re-intervention: The main reason for this is that dose calculations are sometimes rounded to slightly higher extremes, and therefore the current warning messages are all alerts. In consensus with clinical departments, a 1.1-fold limit was added as a blocking measure and tracked to July 2023 with no further abnormalities. Conclusion: The improved results of this project will be extended to hospitals in the system to enhance the safety of paediatric drug use. However, as there are many different types of drugs, there is still a need to continue to build up data to provide more comprehensive gatekeeping.