Under the framework of the TRIPS Agreement, the localisation of the drug test data protection system urgently needs to re-examine the function and system positioning of the system. The article takes the innovative drug Alectinib as an empirical sample, and combines legal analysis to argue the intellectual property attributes of drug test data and the institutional logic of its protection. Research shows that compound patents have inherent defects such as insufficient stability and loss of market monopoly period, superimposed on the lack of data protection system, which seriously weakens the expectation of innovation returns. The data protection system is not only a subsidiary tool of patent law. It needs to break through the understanding of "patent supplement theory" and embed public welfare constraints in the allocation of rights. China should build data protection rules that take into account institutional independence and system coordination, so as to balance the dual goals of innovation incentives and national health security.