Combined with the practice experience of Sun Yat-sen Cancer Center in data quality evaluation and supervision based on the medical big data platform, the paper elaborates the technical framework of the application of this mode, including the construction method of the big data platform and the data quality evaluation model, and the calculation method of quantitative score for each dimension, analyzes the phased results, effectiveness and innovation of the application of this mode, and provides feasible mode and thought for hospital data quality evaluation.