The SLIM parameter has clear error to its real value on the base of the RIM parameter measurement method because it has larger air gap and edge effect. This paper proposes a new scheme suited for SLIM parameter detection. It only needs input total power, phase voltage, phase current, frequency, and then computes primary resistance, primary leakage induction, secondary resistance, secondary leakage induction, air induction and iron loss resistance. The performance analysis of SLIM indicates that this method is very effective and valuable.