Abstract: Digital polymerase chain reaction (dPCR) technology can provide absolute quantitative detection for the target nucleic acid molecules of low concentration, which has great value of application in detecting and curing various kinds of disease. A low-cost and highly integrated digital PCR device based on smartphone and microfluidic chip has been developed aiming at reducing the cost and the redundant volume of currently reported commercial dPCR instruments. The fabrication process of the hardware system was presented. With the help of temperature control circuit and the thermoelectric cooler, the PCR temperature cycle was precisely controlled by the PID controller. The fluorescence image was processed through the adaptive threshold segmentation method, and the result was calibrated by the rule of Poisson distribution, thus the analysis and detection of the result PCR fluorescence image was accomplished.