Aiming at the demand for a low-cost, low-complexity omnidirectional wireless power transmission system under the ubiquitous monitoring background, a omnidirectional wireless power transmission system using a single power source is proposed from the perspective of coil design. The transmitting coil of this system is designed as a six-sided connected cube made of one wire, and the receiving coil is a single rectangular coil. With the simulation of magnetic field distribution and mutual inductance, the optimal coil structure is selected. Experiments show that transmission power and efficiency at any angle of transmitter coil can meet the requirements of wireless power transfer system. From the two aspects of transmission distance and angle, the omnidirectional power transfer law is summarized for the installation range of optimal receiver coil.