The invention relates to an isolated serial liquid crystal driving system based on current direction. The isolated serial liquid crystal driving system comprises a master control microprocessor, a master control microprocessor isolation module, a current signal driving module, a driving cable, a serial liquid crystal displayer isolation module and a serial liquid crystal displayer which are connected in turn. Current direction control refers that high and low level in the master control microprocessor isolation module is converted into the form of the current direction by the current signal driving module and then converted into the corresponding current direction by the serial liquid crystal displayer isolation module through transmission of the driving cable. The isolation conversion circuit of one side of the master control microprocessor and the isolation conversion circuit of one side of the serial liquid crystal displayer are completely independent by the intermediate driving cable which has no electrical connection with any side of circuit so that the installation position between the master control microprocessor and the serial liquid crystal displayer is enabled not to be limited by a digital circuit.