In order to screen out high-efficiency biological pesticides for controlling rice water weevil, Beauveria bassiana WP（10 billion/g）, WP（10 billion/g） + matrine, matrine, Metarhizium emulsifiable powder（10 billion/g）were carried out on the indoor bioassay of the rice water weevil, and the death of the rice water weevil began to be observed 24 hours after the application of the bacteria. The results showed that WP（10 billion/g） + matrine had the smallest LT₅₀ of 122.27 h and the highest corrected mortality rate of 89.47%, the LT₅₀ of which was 36.65% and 41.28% shorter than single dose of Beauveria bassiana and matrine, respectively. Compared with a single dose of Beauveria bassiana and matrine, the corrected mortality rate increased 13.32% and 15.91%, respectively. The combination of Beauveria bassiana and matrine has an additive or synergistic control effect.