The invention discloses a microdetermination method for measuring minimum inhibitory concentration and minimal bactericidal concentration of cationic antimicrobial peptide. The method comprises the following steps: 1) preparing a reagent, namely preparing an MHB culture medium; 2) preparing bacterial suspension, namely reviving the bacteria to logarithmic phase, and preparing bacterial suspension with a certain concentration; 3) counting the bacterial suspension, namely performing coubling dilution on the bacterial suspension in the step 2), dripping and counting; 4) diluting the agent, namely performing coubling dilution on the agent to different testing concentration gradient; 4) measuring the minimum inhibitory concentration, namely mixing and culturing the diluted agent in the step 4) with the bacterial suspension prepared in the step 2), and observing whether macroscopic bacterial precipitation exists; and 6) measuring the minimal bactericidal concentration, namely culturing the testing dripping plate with the antibacterial effect in the step 5), and observing whether colony growth exists. The method for measuring the minimum inhibitory concentration and minimal bactericidal concentration of cationic antimicrobial peptide has the characteristics of low interference, trace, convenience and rapidness.