The invention belongs to the field of helicopter atmospheric systems, particularly relates to a helicopter take-off and landing speed fusion algorithm, and aims to solve the problems of take-off and landing speed fluctuation and time delay of a helicopter and fulfill the aim of lowering a time delay characteristic while reducing fluctuation. The helicopter take-off and landing speed fusion algorithm is a second-order integral operation algorithm with negative feedback control; an inertial vertical acceleration is taken as an input quantity of integral operation; and an atmospheric pressure height is taken as an observed quantity of the negative feedback control. The helicopter take-off and landing speed fusion algorithm has a long-term stability characteristic in the prior art, but is remarkably superior to the prior art in fluctuation and time delay characteristics, is beneficial to flight control, and contributes to enhancing the flight quality.