Embodiments of the invention relate to the technical field of aircrafts, and disclose a method and device for estimating angle and 
angular velocity of a holder motor, a holder, a photographing 
assembly, and an aircraft. The holder is used for carrying a photographing device. The holder includes a base and a motor. The photographing device is connected with the base through the motor. The photographing device is provided with a first 
inertia measurement unit, and the base is provided with a second 
inertia measurement unit. The method includes the steps: acquiring a first 
angular velocity measurement value collected by the first 
inertia measurement unit, and acquiring a second 
angular velocity measurement value collected by the second inertia measurement unit; determining the angle of the motor according to the first angular 
velocity measurement value and the second angular 
velocity measurement value; determining the angular velocity of the motor based on the angle of the motor, the first angular 
velocity measurement value, and the second angular velocity measurement value. The method can reduce the cost in obtaining the angle and angular velocity of the holder motor, and effectivelyimproves the 
estimation accuracy of the angle and angular velocity of the holder motor.