The basic principle and application of automatic liquid calibration instrument were introduced, and a scientific and effective method to verify and evaluate whether the instrument has cross-contamination and accuracy was established. It is proved the instrument have good mechanical accuracy by testing the position of the mechanical arm of the automatic liquid calibration instrument. It is proved that there is no cross-contamination in the process of preparation by determining  blank of the entire process. It is proved that good linear correlation and absorbance can be obtained by drawing standard curve. It is proved that the instrument can obtain higher accuracy by comparing and analyzing the data with man-made data. It is pointed out that the laboratory should establish quality control procedures and corresponding operating instructions, regularly calibrate and functional check the instrument to ensure its long-term stability and reliability, and the accuracy of experimental data.