The utility model discloses a simulation excavation apparatus of a tunnel pipe roof construction method. The simulation excavation apparatus comprises a three-dimensional model testing framework, a loading device, a rock-soil body model, a pipe roof supporting structure and a model monitoring system. The three-dimensional model testing framework is a cubic case type structure with an opening at the top. The loading device is arranged above the inner structure of the whole framework. A reaction plate and a top plate are connected by jacks by which the top plate is enabled to have a downward loading displacement. The structural cavity inside of the integral framework is filled with the rock-soil body model. The pipe roof supporting structure horizontally and transversely drills into the rock-soil body model above a tunnel engineering portal. The model monitoring system is composed of a foil gauge installed on a single tube and a sensor pre-embedded in the rock-soil body model. According to the simulation excavation apparatus provided by the utility model, dynamic construction process of the tunnel engineering under the pipe roof supporting structure is approximately simulated through indoor testing, and dynamic stress and strain process of the pipe roof construction is accurately obtained.