The invention provides a photoelectric comprehensive experiment platform. A single-lens pentaprism of an optical path selection assembly is placed into a mounting base provided with a magnet on a bottom plate. The complexity of alignment of optical elements is lowered through the single-lens pentaprism or two cascading optical paths built quickly. Tedious work of fastening through screws as well as rising and falling of an adjusting frame is not required. A user can set up the optical paths flexibly and conveniently as needed. Due to replaceability of a photoelectric sensor module, a photoelectric sensor probe can be expanded at will. By the adoption of a modular design, an expansion interface is reserved to achieve expansibility of functions of photoelectric experiment teaching instruments. By the adoption of the design of electrical parameter measurement and optical parameter measurement, a measuring meter can be provided for the user to carry out a designable experiment. By the adoption of the design concept of embedded experimental instruments and zero configuration, assistant experimental equipment including an conventional multimeter, an optical power meter and an illuminometer is not needed, and a personal computer is not needed either. The experiment platform is both an experiment teaching instrument and a test instrument, thereby having multiple functions.