At present, the simulation models of UHVDC transmission control and protection system are mainly based on typical control and protection structures, which makes it hard to simulate actual UHVDC transmission characteristics. Besides, most commercial simulation softwares provide encapsulated modules, which are difficult to modify and customize modeling according to the actual situation. For the reasons above, it is of vital importance to establish an open-style UHVDC transmission control and protection model to simulate the characteristics of actual UHVDC transmission projects. ADPSS has unique advantages in modelling AC/DC hybrid power grid because it can realize hybrid electromagnetic and electromechanical transient simulation of large-scale AC/DC power system. Using ADPSS, it builds an open-style UHVDC transmission control and protection system based on practical projects, including converter control, the commutation failure prevention and the commutation failure protection. The accuracy and effectiveness of the model are verified by comparing the outputs of control instruction step response simulation and inverter side AC fault simulation with the same measurements of practical experiment. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900800).