The invention relates to an indoor multimedia system based on a BIM technology. The system comprises a BIM operation and maintenance controller and a multimedia mechanism, the multimedia mechanism comprises a lighting lamp, a smart television, a stereo and a power amplifier, a working power supply module comprises a working power supply circuit, and an audio frequency control module comprises an audio input circuit; in the indoor multimedia system based on the BIM technology, the BIM operation and maintenance controller is used for simulating the indoor multimedia system, and then the construction period of the system can be prolonged and the practicability of the system can be improved; in the working power supply circuit, by means of output of the fourth end of an integrated circuit, conducting of a first triode is controlled, and reliable adjustment of a transformer on supply voltage is achieved; meanwhile, voltage stabilizing processing is conducted on output voltage through a third diode and a fourth diode, and the stability of the output voltage is improved; more than that, in the audio input circuit, by making an LC series resonance circuit access an emitter of a second triode, the high frequency loss in the recording process is overcome, and the reliability of the system is improved.