Abstract: There are a variety of microbes in the environment of the Earth and spaceflight. The proliferation of these microbes especially the pathogenetic microbes in the spacecraft will threaten astronauts＇ health even lives, so rapid and accurate detection of these microorganisms is put on schedule. Among so many detection methods, surface plasmon resonance biosensor developed rapidly in recent years by merit of its rapidness and high sensitivity. The SPR phenomenon occurs when an incident beam of p-polarized light of a given wavelength strikes the surface at a given angle through a prism, the biosensors based on SPR principle are used to monitor the changes of refractive index of ultrathin organic films at metal surfaces and are widely applied in the interaction of antigen-antibody, DNA-DNA and so on, but the harsh conditions of space bring forward more demands for the sensor. Because the detection of SPR sensor is independent of the gravity and it can resist the interference of electromagnetic, sound and so on, the SPR sensor has great advantages in the application of space. This article summarizes the application of SPR biosensor in the microbial detection, aiming at providing reference to microbial monitoring of earth and spaceflight.