Micro-rheological measurement device and method for measuring viscoelastic fluid

The invention relates to a micro-rheological measurement device and method for measuring viscoelastic fluid. The micro-rheological measurement device comprises a laser device, a laser beam expander, a variable diaphragm, a sample tank, an optical fiber probe, a photoelectric detector, a digital correlator and a computer, wherein laser emitted by the laser device sequentially passes through the laser beam expander and the variable diaphragm to be illuminated to fluid in the sample tank; a rear end of the sample tank is used for placing the photoelectric detector for collecting scattered light; the optical fiber probe is connected with the photoelectric detector and is used for measuring the strength of the scattered light; the photoelectric detector is connected with the digital correlator and is used for calculating a self-correlation function of the strength of the scattered light; the digital correlator is connected with the computer and is used for calculating the fluid viscoelastic coefficient according t