Loading cryoprotectants (CPAs) into oocytes is critical to restrain ice formation during cryopreservation. However, high concentration of CPAs may cause osmotic and toxic damage to oocytes. In order to minimize the osmotic damage, a microfluidic device for loading CPAs into oocytes was designed and fabricated in this study. 30% (v/v) Me₂SO was linear loaded into porcine MⅡ-stage oocyte with the microfluidic device, the intracellular CPA concentration, the cell volumetric changes and the effect on the survival rate and developmental rate of oocytes were investigated and compared with the traditional methods including the one-step method and the step-wise methods. The results showed that the microfluidic method can realize continuous CPA loading to oocytes, reduce the osmotic shock to cells and enhance the cell viability. The lowest penetration volume of oocyte reached 0.86V₀. The cell viability was 92.8% with the microfluidic method, ～33% higher than one-step method, ～16.3% higher than two-step method, and no significant difference with four-step method. After parthenogenetic activation and cultured in vitro, the cleavage rate and the blastocyst rate of oocytes were 75.8% and 27.4%, which were significantly higher than the one-step method and the step-wise methods (P < 0.05). In conclusion, linear loading CPAs with the microfluidic method can significantly alleviate the osmotic damage to oocytes, which may provide a new path for oocyte cryopreservation.