An autonomous measurement method of height based on the asynchronous vision of a single feature point is proposed, in which the internal and external matrix are calibrated separately and thus the computational efficiency is high. This method is verified in the constructed flight simulation device with six degrees of freedom and the results show that, below the testing height of 2 m, the absolute measurement error is less than 0.02 m and the relative error is superior to 1.5%. This method requires a less computing load, and is particularly suitable to the application of fast decoding in planes, and can also be extended to the measurement application of the ground target positioning.