The switching characteristics of nonlinear optical fiber-loop mirror (NOLM) for continuous wave are different under different pumping conditions. When the pump peak power is greater than the switching threshold power, it is found that the transmitted waveform of single-pumped NOLM has the feature of inverting pump pulse peak and one transmitted pulse is generated respectively at the corresponding rising and falling edges of the original pump pulse. The double-pumped NOLM has the function of comparing pulse peak power of two input pump pulses which have the same parameters except for the power and wavelength, and output pulse power is determined by the deviation of the peak power of two pump pulses. Based on two above characteristics of NOLM, a scheme is designed for all-optically separating the pulses from the same input signal with two-level power. Numerical simulations are executed by using photonics simulation software. The results show that two-level power signal is separated successfully, and output signals are loaded to different wavelengths respectively. No pedestal is observed at the separated output higher-level power pulses. So the scheme also has the ability to eliminate pulse pedestal.