Due to the excellent comprehensive properties of advanced ceramic materials, such as low density, high hardness, high rigidity, high wear resistance, low coefficient of thermal expansion, high thermal stability, chemical stability, non-magnetism, etc., ceramic balls such as silicon nitride have been widely used in high-speed, high-precision and special environmental requirements bearings. Machining load is considered as the most important machining parameter of ceramic ball grinding, which directly affects the balling process, machining efficiency and machining quality of ceramic ball grinding. In this paper, silicon nitride Si3N4 ceramic balls are taken as the research object, the influence of machining load on machining process is discussed, and a new loading device and its control system are developed in view of the limitations of the existing loading system. The main work and achievements of this paper are as follows: 1. In order to master the influence of different processing load strips on the processing process of ceramic balls, theoretical analysis, experimental research and numerical simulation methods were used to discuss the influence of different loading conditions on the balling process of ceramic balls, surface material removal forms and surface quality. The results show that the smaller machining load can achieve better size selectivity, thus improving the correction effect of spherical error. When the load is large or the concentration of abrasive particles is low, the material is mainly removed in the form of two-body wear. On the contrary, the material is mainly removed in the form of three-body wear. When the material is removed in binary form, the material removal rate is higher. The surface materials of ceramic balls are mainly removed in the form of brittle cracks. Lower grinding pressure is beneficial to obtain better surface roughness and reduce the occurrence of surface damage such as cracks. 2. In order to meet the requirement of high-precision loading, a device driven by stepping motor to precisely pressurize worm gear is proposed, and a new type of loading device is developed for the double-rotation precision ball grinding equipment developed by the research group. In the loading system, the stepping motor is used to press down the worm structure to deform the pressure spring to generate pressure, and the pressure value is measured by the pressure sensor. The worm reducer has a self-locking function, thus ensuring the constant pressure of the upper grinding disk. The maximum loading force of the loading device is 10kN, the loading accuracy is 5‰, and the minimum loading force is 50N. It can completely meet the needs of ceramic ball finishing. 3. Design a new loading mode control system. The load control method is selected as digital recursive PID control formula; The loading controller MCU adopts C8051F MCU of Cygnal; Select 110BYG stepping motor; Select UCN5804B integrated circuit chip as motor drive chip; Acceleration sensor and pressure sensor are selected. The maximum loading force of the selected loading device after assembly is 10kN, the loading accuracy is 5‰, and the minimum loading force is 50N. 4. The new loading method of double-rotation grinding equipment is used to grind the ball blank, and the grinding results are compared with those of the blank under the original loading grinding method. By measuring the sphericity, surface roughness and other parameters of the processed ball, the sphericity and surface roughness of the blank ball under the new loading method are better than those under the original loading and grinding method, and the ball removal rate under the two loading methods is not much different. Through theoretical analysis and experimental verification, the designed new loading method can achieve high-precision loading requirements, and can completely meet the demand of load control in ceramic ball finishing.