The invention relates to a communication method for weighing 
system based on digital sensor, which requires files building of a key and its 
password on 
release date as well as a key for digital sensor. The process of the said method is that: firstly, the key and its 
password for the storage 
system of the weighing instrument are downloaded to the digital sensor, from which the key and its 
password on 
release date can be obtained; secondly, the weighing instrument sends the communication orders to the target digital sensor, and the encrypted data packet, encrypted and generated through key files of digital sensor, data flow and 
system cipher, is sent to the target digital sensor; thirdly, after monitoring and receiving the packet, the target digital sensor will make a deciphering and 
recovery to obtain the system 
raw data by system key and key on 
release date, and then take it as the communication order; fourthly, after receiving the communication order, the target digital sensor will make a data packet of the sampled weights, and the data packet, the key on release date and the system 
cipher, encrypted and generated as the release encrypted data packet, will be sent to the weighing instrument; lastly, after monitoring and receiving the release encrypted data packet, the weighing instrument will make a 
encryption to obtain the weight data by system 
cipher and key on release date. Thus the transmission and communication of weight data is achieved. The invention ensures a security and reliability of the channels for weight 
data transmission.