A light-reflection adaptive photoheterodyne probing method features only use of a light-reflective crystal PR. The signal beam and laser beam as pump beams are simulteneously emitted into the PR. Regulating their incident positions and incident angles can make PR work in phase-conjugated self-pump and mutual-pump coexistance state to generate the reflelected self-bump and mutual-pump beams, whichhas consistent optical pathes and are collimated and front matched on the photosensitive surface of photodetector. Its advantages are high S/N ratio and sensitivity, simple structure and easy regulation.