The utility model relates to an Internet of things connecting system comprising a plurality of internet of things routers; the internet of things router comprises a wireless route unit and a microprocessor module connected with the wireless route unit and suitable for receiving wireless data; the microprocessor module is suitable for providing Homeplug AV protocol and carrying out OFDM modulation/demodulation; the internet of things router also comprises a DA module connected with a digital signal emitter end of the microprocessor; a simulation signal output end of the DA module is connected with a coupling module used for coupling a simulation signal outputted by the DA module to a power line and conveying the signal to the corresponding internet of things router; the coupling module is also connected with an AD module, so the signal, conveyed by the power line, of the corresponding internet of things router can be received by the AD module; the AD module is connected with a digital signal receiving end of the microprocessor module. The internet of things connecting system solves the problem in the prior art that a conventional internet of things router has poor coverage in a complex building environment through a wireless sensor, thereby enlarging a construction scope of the internet of things.