A distributed remote collaborative hybrid test (RCHT) method for complex substructures based on OpenFresco is presented in this paper. Challenges in the RCHT include the modeling of the numerical substructure, boundary degreeof-freedom (DOF) loading, and equivalent communication of the multi-story space frame as a test substructure in OpenFresco. The effectiveness and accuracy of the proposed RCHT method are verified by a series of remote distributed tests that reproduce the seismic response of a three-story five-span space Y-shaped eccentric brace steel frame model consisting of two test substructures and a numerical substructure. The main contributions of this study are the realization of the multi DOF loading RCHT of the space global frame and reasonable simplification of the substructure boundaries, which further promotes the use of the RCHT method to realize the seismic performance simulation of complex substructures.