Platform blocking behaviour has the characteristics of special subject，diversity of behavioural purpose and complexity of behavioural effect，etc.. In judicial practice，judges find it difficult to accurately grasp the improper determination of such behaviour. In terms of legal basis，the application of Internet special articles has limitations，and should be identified by general articles；in terms of identification paradigm，the existing industry practice principle，the principle of least privilege and other adjudication rules have defects such as the application basis is to be tested，the scope of application has limitations，and the effect of application has deviations. Based on this，the regulatory concept，timing and method of regulation of platform blocking should be clarified on the macro level，and the principle of proportionality should be introduced as a specific method on the micro level，so that the appropriateness of the purpose，the necessity of the means and the balance of the result can be considered to see whether the behaviour constitutes unfair competition，thus solving the conflict between the private right of the platform operator’s exercise of power and the public nature of the symbols of power，and realising the balanced protection of diversified interests.