The invention relates to a data collection communication system. A processing unit is connected with a data acquisition module, a data backup module, a communication module and an upgrade module. The processing unit is a MCU with an internal timer, and further provided with an ADC interface, an I2C interface, a SPI interface, an external bus interface and a network controller interface. The method comprises the following steps that the processing unit can upgrade a backup storage in the upgrade module by judging the type of a received command, upgraded program data received by the communication module are written into the backup storage through the processing unit, a main program storage is disabled, the processing unit is reseted, and the upgraded program data are transferred into the processing unit to be conducted from the backup storage in a program form. By the adoption of a plurality of data collection modes, the data collection modes and methods are expanded, the diversity of collection method of system front-end data is increased, the system can be upgraded and operated online when hardware equipment is not changed, and cost of the required manpower and material resources for upgrading the system is reduced.