The SoftPLC technology is a new control technique based on personal computer（PC）. A realization scheme for applying SoftPLC technology in the smart protection and measurement unit and a feasible system structure are proposed to implement on-line programming and simulation of the smart protection and measurement unit logic， and at the same time the on-line configuration of unit parameters. By using SoftPLC technology， the logic realization correctness， reliability and engineering application flexibility of the smart protection and measurement unit are enhanced and the development period is shortened.