Orbital net capture is an innovative mission concept, and has special potential on space debris disposal and OOS (on-orbit service). Dynamics of orbital net casting is a key technique of the orbital net capture system design and application, for which two major feasible investigation means have been suggested: dynamic modeling, simulation and ground test. Based on dumped-mass model, a model of the system dynamics was derived, and a ground test device was designed to verify the simulation result. The comparison of several ground tests and simulations shows that the model can be used to design orbital net capture systems. Relevant pictures of ground test and simulation were presented.