Modulation measurement profilometry is a vertical 3D measurement technique, which can measure the complex objects with acute changes in their surfaces. A fast modulation measurement profilometry based on orthogonal spatial carrier is proposed. In this method, two cross-sinusoidal gratings at a certain interval are imaged on the surface of the testing object which is laid between two imaging planes of them. We can separate the images of orthogonal gratings through spatial frequency domain filtering, obtain the modulation distribution images of two cross-sinusoidal gratings, and then restore the height of the object through the map of the ratio of modulations and the height. It is convenient to obtain the height using only one captured image, so the main characteristic of this method is real-time 3D information collection. The experimental result proves that it can restore the height of the object fast and more accurately.