The laser fluorescent correlating spectrum single molecular analyzer is used in the research of single molecule inside solution in life science, chemistry, physics and other fields. The sample solution is set on cover glass or sample pond; the laser beam, after being beam expanded, filtered in exciting filter, reflected in the dichromatic mirror and focused in the objective of microscope, irradiates the sample solution to excite the molecule under research; the fluorescence the sample solution emits is made to pass through the same objective, the dichromatic mirror, emitting filter to eliminate hybrid light, lens to focus and pinhole coupled to reach the single photon detector; and the signal the single photon detector generates is acquired with the data acquisition card and processed in the computer. The present invention has the features of simple operation, high stability, less light loss, high sensitivity, etc. and may be used in various basic researches.