Abstract: 【Objective】 To evaluate the control effects of plant protection unmanned aerial vehicle (UAV) as sprayer on Chromaphis juglandicola (Kaltenbach) and Cnidocampa flavescens (Walker) in walnut orchards, so as to provide theoretical reference and technical support for control of walnut pests by plant protection UAV. 【Method】 Field spraying with plant protection UAV, investigation of insect pest decline rate, calculation of control effects and variance analysis. 【Result】 The ground loss rates of pesticides sprayed with plant protection UAV were less than 10% in walnut orchard after adding 0.5% spray adjuvant. And the control effect of 70% imidacloprid (The dose was 150 g/hm²) was 96.05% against C. juglandicola on the outside leaves and the average control effect was 80.37%, which was significantly higher than that of 22% thiamethoxam·lambda-cyhalothrin (The dose was 375 g/hm²) and 25% cycloxaprid (The dose was 300 g/hm²) on the 14 days after application. The average control effects of 22% thiamethoxam · lambda-cyhalothrin (The dose was 525 g/hm²), 1.2%matrine·nicotine (The dose was 1,050 g/hm²) and 3.2% abamectin (The dose was 525 g/hm²) against C. flavescens were 98.17%, 90.39% and 95.46%, respectively on the 10 days after application. There was no significant difference between the three treatments. 【Conclusion】 When adding spray adjuvant, the control effect of 70% imidacloprid against C. juglandicola in plant protection UAV is over 80%, the control effects of 22% thiamethoxam·lambda-cyhalothrin, 1.2% matrine·nicotineand 3.2% abamectin against C. juglandicola are 90%.Plant protection UAV can be used to spray the above pesticides to control C. juglandicola and C. flavescens in production.