Deep space life exploration nowadays mainly focuses on whether environments on other planets are suitable for the
existence of life. This has not hit the key point. As life depending on its specified conditions, it is of great necessity and
importance to conduct exploration in the life's original environment. An idea was put forward in this paper to detect
specific life forms in the original environment if they exist. This idea, based on fluorescence, included light source unit
and detection unit. The former was optical fiber coupled LED and lens; the latter was charge coupled device (CCD) and
other lens. Light from LED was collected and transferred by optical fiber, then purified by a filter in order to obtain
specific wavelength light, which could excite corresponding organic biological molecules. These molecules emitted light
of other wavelength, usually referred to as fluorescence, the moment they were illuminated by excitation light. The
fluorescence was also purified by another filter. Then lens was used to collect the light. As to detection device, CCD
would give fluorescence image. Theoretical analysis demonstrated that the system could meet the task's requirements.
During test in laboratory, this system performed well, too. CCD could output desired signals. This provided strong
support that the idea present in the paper is feasible and is of practical significance.