The utility model provides a screening method used for herbicide high flux 96-hole orifice plate. The utility model adopts the technical proposal that: firstly, exponential phase chlorella is inoculated on the 96-hole orifice with a culture medium which is suitable for the chlorella, and the initial inoculating number of the chlorella is 7 to 8 x 105 per mL; secondly, the concentration gradient herbicide is dipped into each hole, and each concentration is provided with two to five duplicate samples as well as an empty control sample. The culturing condition is that: temperature is 25 plus or minus 0.2 DEG C, light is 2000Lx, continuous light is kept, fresh-keeping film is used to seal, no nutrient solution is added, chlorella solution is aerated four to five times every day, the chlorella is cultivated 72 to 144 hours in total, test sample is measured at 630nm absorbance every day, and then the EC50 (median effect concentration) of the herbicide on the chlorella is calculated according to the relationship between the absorbance and the herbicide concentration. Compared with the flask method, the utility model has the advantages of reducing herbicide amount in screening, and having easy operation, fast speed and high sensitivity.