Measuring method for displacement efficiency of simulated well cementation cementing

The invention relates to a measuring method for displacement efficiency of simulated well cementation cementing, which comprises the following steps: 1) taking a PIV (Particle Image Velocimetry) system as a measuring device; 2) respectively injecting a displaced solution and a displacing solution into a simulated shaft and distributing tracer particles in a displacing solution flow field; 3) causing the tracer particles to generate scattered light through a laser of the PIV system, and shooting and recording the positions of the tracer particles in the flow field in real time by using a CCD (Charge Coupled Device) camera of the PIV system; 4) obtaining a moving image of the tracer particles in the flow field, selecting a group at equal intervals from the moving image as analysis identifying information, and obtaining the areas occupied by the tracer particles in different time periods in an annular cross section of the simulated shaft; 5) obtaining the displacement efficiency of the displacing solution for the displaced solution in a certain time period according to the total area of the annular cross section of the simulated shaft and the data obtained through analysis identification; and 6) drawing a displacement efficiency graph through the obtained displacement efficiency in the simulated shaft in different time periods, thereby obtaining the whole displacement efficiency in the simulated shaft.