The invention discloses a split-type mini multifunctional concrete temperature intelligent on-line monitoring system. An encoder chip (3) comprises an IIC storage chip. The IIC storage chip is used for storing serial number information in one-to-one correspondence to temperature sensors. An acquisition system is connected to the two ends of a temperature acquisition resistor (2) through a temperature line and a GND line; and the acquisition system is connected with the IIC storage chip through an IIC frequency line and an IIC data line. Each measurement interface can be expanded, thereby greatly increasing the number of the sensors; the system supports mix-match measurement of thermistor, platinum resistor and copper resistor sensors; each sensor has unique identification, and sensor can be located conveniently after line breaking, thereby effectively improving sensor survival rate, and ensuring no blind point of temperature monitoring; the system can realizes the following functions through software: carrying out automatic alarming when the system exceeds a safety value, carrying out GPS positioning and theft prevention, and realizing spot measurement, subsection cycle measurement and automatic cycle measurement and the like; and the system has reserved auxiliary function interfaces selectively used as needed for environment condition monitoring and external power source and the like, and the effects of convenient realization and plug and play are achieved.