High voltage dedicated line in power system substation often experiences difficulty in collecting electricity bill from user after power consumption,thus seriously affecting the production and operation of power supply enterprise.A corresponding monitoring system was developed for this.The principle of the monitoring system was introduced,the data collector in the monitoring system was analyzed,and the application effect was provided.The monitoring system is applied to user of high voltage dedicated line in substation,which can effectively avoid the phenomenon of user defaulting on electricity bill.