The invention discloses a complicated electromagnetic environment construction system which comprises a square chamber. The square chamber is internally provided with three sets of electromagnetic wave transmitting devices with different frequency bands. Each electromagnetic wave transmitting device comprises a base which is connected with bottom of the square chamber. Each base is provided with apolarization turntable. Each polarization turntable is provided with a loudspeaker antenna array. The orientations of the three loudspeaker antenna arrays are same. Each loudspeaker antenna array isconnected with a signal input interface through a feeder line system. Each base and each polarization turntable are connected with a control unit through a communication control interface. The controlunit is connected with a keyboard and a display device. The system satisfies a requirement for a wide-band high-power electromagnetic environment and can directionally transmit a high-power microwavesignal from a same-band transmitter to a preset position, and is used for generation of an EMC electromagnetic environment. In a high-power state and a required distance range, an electromagnetic wave signal which can satisfy a use requirement is generated for realizing construction of a complicated electromagnetic environment.