Concerning to problems of the traditional machine pitch system for miniaturizing Micro Air Vehicles (MAVs), A novel asymmetrical pitch method is put forward in this paper. This novel method makes use of the deformation of an elasticity link to generate the blade pitch meeting the requirement of the MAV flight mode control. This new pitch mechanism has been verified by means of two experiments. One experiment measures blade pitch angle by a non-contact measurement using the high speed camera and image processing and the other experiment measures deformation of the elasticity link which is key part in asymmetrical pitch system based on strain gauge and rotating electrical connector. From relationship between blade pitch angles and the output torque of the main motor and deformation curves of the elasticity link, the pitch mechanism that the deformation will periodically change once with the rotor blade rounding a lap is proved.