The invention provides an extreme speed PCR reaction detecting device, which comprises a temperature control system, a horizontal transmission mechanism, a reaction tube fixing device, and a perpendicular transmission mechanism.The horizontal transmission mechanism drives the temperature control system to move horizontally, the reaction tube fixing device is connected with the perpendiculartransmission mechanism and capable of moving up and down along an eccentric wheel of the perpendiculartransmission mechanism so as to realize the relative reciprocating movement of a reaction tube on the reaction tube fixing device between temperature control modules. The extreme speed PCR reaction detecting device is compact in structure, the moving speed is fast, the temperature rising and falling speed of reaction liquid in the reaction tube can be increased by the temperature setting of a high temperature module and a low temperature module, the two aspects of increasing the temperature rising and falling speed of the reaction tube and the moving speed between the reaction tube and the temperature control modules are set about to achieve the purpose of shortening the time required for PCR reaction, at the same time, the detection result of the extreme speed fluorescence PCR reaction detecting device is good in repeatability, and the result is accurate.