Abstract: In order to improve the conversion efficiency of the laser wireless power transmission system, based on the working principle of single junction GaAs photovoltaic cell, by the method of adjusting the parameter of laser which irradiated the photovoltaic cell, an optimization scheme was designed to each part of the laser wireless power transmission system theoretically. The relation between the conversion efficiency with laser wavelength and incident intensity was measured experimentally and discussed theoretically. The results show that the conversion efficiency of GaAs photovoltaic cell is improved obviously compared with monocrystalline silicon photovoltaic cell for monochromatic laser. The maximum conversion efficiency reaches 61.2%. The conclusions have a certain reference value for the application of laser wireless power transmission.