The invention relates to a multifunctional input/output interface board, which comprises an optoelectronic isolation input circuit, a logic control circuit, a display and communication circuit, and an output control circuit, wherein the optoelectronic isolation input circuit consists of an optoelectronic isolator and a light-emitting diode connected in series, the input end of the optoelectronic isolation input circuit is connected to an external sensor, and the optoelectronic isolation input circuit is used for performing anti-interference filtration and noise reduction treatment on input external signals; the logic control circuit receives signals processed by the optoelectronic isolation input circuit to realize input/output control; the display and communication circuit receives control signals of the logic control circuit and performs parameter configuration and communication with external equipment; and the input end of the output control circuit receives the control signals of the logic control circuit and the output control circuit outputs switch control signals to on-site external serial-port equipment. The multifunctional input/output interface board can be used for signal input of various sensors, automatic control of switch signals and communication interfaces with digital instruments on industrial site, and solves the problems that interface signal levels on the industrial site are not matched or common-grounded, interference of the various noise signals in the prior art is not eliminated, and the like.