The invention discloses a phase object Z-scan-based pump-probe method, which includes the following steps: an incident
laser beam is split into two beams, the beam with
high intensity is pump light, the beam with low intensity is probe light, and the pump light is delayed and focused on a non-linear sample to be tested, so that the sample to be tested, which is in the
ground state, generates non-linear absorption and non-linear
refraction; the sample to be tested is located on the focal plane of a lens in a probe light path, a round diaphragm and a round baffle, the centers of which are superposed with the
optical axis, are placed at a far-field position in the probe light path behind the sample to be tested, the emergent probe light is split into two beams by a spectroscope, one of the beams directly enters a first probe, and the other beam enters a second probe after passing through the diaphragm and the baffle. A measuring
system which operates according to the method is
highly sensitive and can simply process data, non-linear absorption and non-linear
refraction can be measured simultaneously rather than separately, and the method has the advantages of accurate measurement results and the like.