DDG-1 multichannel intelligent flow integrator/controller is made from MCS-51 monolithic computer. Generally, it is used as a multichannel integrator. With the aid of temperature sensor and pressure transducer,it can real-timely detect the medium temperature and pressure. Using the highly precise mathema tical model the flow can be automatically compensated and integrated. Besides, the function of automatic diagnosis enables it to detect the faults of the instruments by acousto-optic alarming. The working principle, automatic compensating principle and application software are presented in the paper.