Abstract: Abstract: It is generally known that egg weight classification is one of the most important processes of egg production, processing and sales. In order to improve the production efficiency and accuracy of egg grading, this paper introduces a synchronous tracking automatic control system, which is used for electronic weighing and grading packaging of eggs. This new system is based on the task group design of egg grading packaging machine, and composed of 4 parts, namely, a weighing part, a grading part, a loading plate part and an automatic feeding part. The egg grading packaging process includes egg weight detection, data processing, data communication, egg position synchronous tracking and quick boot and reset of electromagnet. Advanced RISC machines (ARM) are used to process egg weight signals collected by multiple-channel sensors, and the weight signal is intercepted in a stable period of time for about 70 ms after the simulation of filter, nonlinear correction, and frequency compensation. Then the system uses the average value to perform filter processing. Firstly the processing of information is through the free port communication protocol, which is sent to the programmable logic controller (PLC) of the register; secondly, the PLC controls to start the corresponding discharge electromagnet by judging the grade of egg weights. Then, as the reference signal frequency of external pulse, the high-speed pulse produced by the encoder precisely is applied to locate the position of the movement of the egg by using the method of data location transmission. Then the corresponding actuators are controlled together with the movement of the mechanical device, and the links of weight acquisition, classification of unloading, traying and sending the disc are completed to achieve accurate grading and packing for the eggs in different weight level range. Three hundred eggs are randomly selected as the experimental samples, and electronic scale weighs actual weight and records data. After using ARM to measure the weight of the egg, the weight information is sent to PLC, which is then real-time displayed in the upper computer and compared with the actual weight. At the same time, PLC controls the corresponding discharge solenoid action, so that the eggs of different weights can fall into the egg transfer tray of corresponding level. After we finish the measurement and grading of 300 eggs, each egg is tested continuously for 10 times and the data are recorded. The experimental results show that the weighing error of this control system is between -1 and 1 g, which accounts for 85.6%; the weighing error of this control system is between -1.5 and 1.5 g, which accounts for 95.3%; and the classification accuracy rate reaches 98%. When the egg weight is at the boundary value of 2 levels, it is likely to be assigned to the wrong class because of the measurement error, which greatly affects the accuracy. The research results can help to improve the production efficiency of egg grading, which provides a reference for the localization of egg grading technology.