With the development of marine military and strategy，it is difficult for traditional acoustics to meet the requirements of air-water cross-medium communication. Magnetic induction communication technology can be used as a technical supplement for air-water cross-medium due to its consistent magnetic permeability in air-water medium and advantages of stable channel，fast speed，flexible volume and low cost. Based on magnetic dipole，this paper has studied the air-water cross-medium induced magnetic field propagation model to prove the propagation continuity of magnetic field at the air-water interface. Besides，a communication transceiver circuit has been designed based on USRP and a magnetic induction communication system has been realized. This system has achieved error-free text transmission with an air-water(lake)cross-medium of 20m and a communication rate of 10kbps under the condition where the radius of the transceiver coil is 10cm and the transmitting power is 1 mW， which has proved the feasibility of magnetic induction communication in air-water cross-medium scenario and provided guiding significance for the subsequent related research.
