Cover Story：With the help of the oocyte cryoproservation, the assisted reproductive technology and the embryo engineering technology have tremendous development potential. However, the high concentration of cryoprotectants(CPAs) in cryopreservation will cause osmotic damage and toxic damage to oocytes. Unlike adding a fixed concentration of CPA in step-by-step method, the microfluidic method can achieve continuous CPA concentration change. The oocytes damage evaluation in CPA continuous loading by microfluidic method has not been reported. In this paper, the osmotic behavior of MⅡ porcine oocytes in different loading time, different loading line types and different concave loading types were simulated. Three traditional parameters ΔV (maximum volume change), AOD(accumulative osmotic damage) and J (accumulative chemical damage) were used to evaluate the damage of oocyte. A comprehensive parameter s, which based on the traditional parameters and the information entropy theory，was proposed to evaluate the damage. Oocytes loading experiments were conducted to verify the effectiveness of s. The results showed differences from the results of traditional damage assessment parameters, which cannot come to the unified conclusion. By analyzing the relationship between blastocyst rate and s, we found that there is a highly negative correlation between s and blastocysts rate. That indicates that the comprehensive damage assessment parameter s can be used to assess cell damage and breaks a new path for cell damage evaluation.