To reduce the time consumption for obtaining pa-rameters of short-circuit current in real-time and accurately

a new algorithm called Recursive Least Square Correction Algorithm（RLSCA）is proposed in this paper.This algo-rithm uses the principle of correcting three different sam-pling start points to eliminate the effect of attenuation com-ponent on calculation result

and uses the recursive princi-ple to optimize the calculation process.It is proved that RLSCA can be applied in the real-time calculation of short-circuit current.The simulative result shows under the condition that the frequency of the power system is50Hz

the sampling mode is64samples per cycle and the SNR is30dB

this method can complete the calculation of the rel-ative parameters of the fundamental wave of the short-circuit current within8ms after the short circuit fault occurs.