In order to improve the efficiency of citrus ploidy detection and reduce the cost of ploidy detection,the effect of reagent dosage,pretreatment method and water supplementation of detection solution on the detection of ploidy of citrus was carried out.The results showed that citrus ploidy could be correctly detected by 25 μL of master mix and then deionized water.The best effect of peak processing is that the amount of deionized water to the mixture in the range of 1,000~1,400 μL,and too much or too little is not good for correct results.The processing efficiency is nearly 2 times higher than that of conventional methods,when the nuclei extraction buffer and staining buffer are proportionally made into a master mix,and the sample is pressed with the thick end of the dissecting needle.In summary,the optimization method obtained in this experiment can greatly reduce the cost of citrus ploidy detection,is practical and convenient,simple to operate,improves the efficiency of ploidy detection and improves the safety of test operation,which is of great significance for the improvement of citrus varieties and the breeding of ploidy varieties.