The instrument can quickly detect DNA or RNA of a biological sample by polymerase chain reaction on microfluidic chip. The prototype has been successfully tested in the laboratory of avian influenza, Ebola and other infectious viruses. The instrument has high test sensitivity and specificity with less use of reagents and samples, which is economical and practical. The instrument can be used widely in POCT testing market, such as spread of communicable disease surveillance and prevention of spread of foodborne bacteria virus detection, some cancer-causing gene mutation detection, etc.