Optical measurement methods based on full-field phase calculation can obtain three-dimensional (3D) shape of object surfaces. Full-field fringe projection profilometry and phase measuring deflectometry are used to measure the shape of diffuse surfaces and specular surface objects, respectively. There are many composite surface objects composed of diffuse surfaces and specular surfaces in industrial production and daily life. Rapid measurement of the surface shape of these objects is the key to ensuring their quality. Therefore, a composite surface 3D shape measurement method based on phase measurement deflectometry and fringe projection profilometry is proposed in this work, and a corresponding simulation system is established. The influence of different structural parameters on the 3D measurement results is analyzed by simulation, and the parameters of the measurement system are optimized to obtain the optimal parameter configuration. Simulation and experimental results show that the optimized measurement system can accurately and efficiently obtain the 3D shape data of composite surface objects.