Aiming at the problems of high labor intensity and low work efficiency in the process of black soldier fly (Hermetia illucens L.) sand collecting, a parallel double impeller collecting device for black soldier fly sand was designed. Firstly, the external dimensions of parallel double impeller were determined according to the agronomic requirements of black soldier fly larvae bio-transforming livestock and poultry manure. By analyzing the working mechanism and dynamics of the parallel double impeller, the curve and quantity of the arc-shaped impeller blades were determined, and the trajectory and equation of the impeller aggregate movement were obtained. On this basis, the main factors affecting its aggregate properties were determined. Then, single-factor and three-factor three-level quadratic regression orthogonal tests were conducted with forward speed, impeller inclination angle, and impeller speed as test factors and the aggregate efficiency and variable coefficient of aggregate uniformity as the response value. Besides, a response surface mathematical model was established to analyze the influence of various factors on aggregate performance, and Design-Expert software was employed to comprehensively optimize the influencing factors. The test results showed that the order of influencing factors on the aggregate efficiency from primary to secondary was as follows: impeller inclination angle, forward speed, and impeller speed; the order of influencing factors on the variable coefficient of aggregate uniformity from primary to secondary was as follows: impeller speed, forward speed, and impeller inclination angle. The optimization results were verified, and it can be obtained that the forward speed was 0.06m/s; the impeller inclination angle was 18°; the impeller speed was 16r/min; the aggregate efficiency was 4.67kg/s;the variable coefficient of aggregate uniformity was 2.81%; the relative errors between the experimental values of each evaluation index and the optimized value of the model were 3.78% and 6.84%, respectively, which met the requirement of black soldier fly sand aggregating and conveying.