电路的参量对其性能并不具有同等的影响，从电路的全部参量中筛选出有显著影响的有效参量，可大大减小宏模型的维数，从而减少建立模型所需的试验。根据二水平析因试验法，提出了二级筛选法，用最少必要的实验数量，有效而精确地选出有效参量，使宏模型满足规定要求。 The parameters of the circuit do not have the same effect on the performance. Selecting the effective parameters with significant influence from all the parameters of the circuit can greatly reduce the dimension of the macro model and reduce the test required to establish the model. According to the second horizontal factorial experiment method, the second-level screening method is proposed. The effective parameters are effectively and accurately selected with the minimum necessary number of experiments so that the macro model can meet the specified requirements.