For problems of contact charging mode of existing mine-used portable methane detector, such as contact would be loose and oxidized, battery life was short under the condition of long charging time, wireless charging technology was proposed for charging mine-used portable methane detector. Wireless charging circuit was designed. On the basis, prototypes of mine-used portable methane detector and wireless charger were developed. The experimental result shows that wireless charging technology can charge mine-used portable methane detector reliably and safely. Distance between sending coil and receiving coil should be smaller for higher energy transfer efficiency.