In view of the current situation that the poor accuracy and low efficiency of automatic weighing and distributing machine while weighing and distributing lead sheets into heaps, a special automatic machine was developed. The overall design about this special machine ,aiming at providing a method for weighing and distributing in a more professional way, was provided and its mechanical motions,master control circuit,software control procedures and algorithm were elaborated respectively. The method called dichotomic optimized matching method in which a proper balance between efficiency and accuracy was maintained by finding the proper adapting degree and the position error which was within a given range of the target variable simultaneously. RS485 communication interface and Modbus communication protocol make data transmission between the following procedures such as packaging and assembling etc possible.