Abstract: In actual application of drip irrigation project with biogas slurry, emitters clogging occurs frequently. This study established models for predicting clogging of emitters and optimized system factors of drip irrigation system with biogas slurry in order to prevent the emitter clogging effectively and improve the reliability of the operation of the drip irrigation system with biogas slurry. The remaining biogas slurry from the actual biogas project was took as test samples. The total solids in biogas slurry was 0.6%, the chemical oxygen demand was 3 722.40 mg/L, the pH value was 8.42 and the turbidity value was 864.20 NTU. From the perspective of controlling the operation mode of the drip irrigation system rationally and meeting the requirement of crop growth, the ratio of water to biogas slurry, irrigation pressure and dripper flow rate were taken as the influencing factors. The ratio of water to biogas slurry included 3 levels of 1:1, 2:1 and 3:1. The irrigation pressure was 0.04, 0.12 and 0.20 MPa. The dipper flow rate was 4, 8 and 12 L/h. Average relative flow rate and first clogging time of the emitters were used as the response index in the experimental study. The experiment was designed by response surface methodology. The model was established by using regression analysis method. Response surface analysis was completed by the software of Design-Expert 8.0.6. The results showed that the ratio of water to biogas slurry, irrigation pressure and dripper flow rate had significant effects on the average relative flow rate and first clogging time of the emitters in drip irrigation system with biogas slurry, and the effects of these 3 factors on the average relative flow rate and first clogging time of the emitters was ordered by dripper flow rate > ratio of water to biogas slurry > irrigation pressure. Under the condition with large ratio of water to biogas slurry and dripper flow rate, the average relative flow rate was the largest and the firs clogging time was the longest. The optimal condition to obtain larger relative flow rate and longer first clogging time obtained by response surface methodology was as follows: the ratio of water to biogas slurry was 3:1, irrigation pressure was 0.14 MPa, dripper flow rate was 12 L/h. Under such an optimal condition, the measured average relative flow rate was 0.83 and the measured first clogging time was 55 h. The relative error between the measured value and the theoretical value of the model was smaller than 4%. It verified the reliability of model proposed in this study for predicting first clogging time of emitter in drip irrigation system with biogas slurry. The study would provide valuable information for the design of emitter in drip irrigation system with biogas slurry.