The invention relates to a force transmission transfer rack use for a liquid rocket engine test and a design method. By analyzing a force transmission route from an engine production point to a test bed support point, and carrying out force simulation calculation in the transmission process of the push force generated by an engine, a force distribution condition of the bottom of a lower ring beam of the transfer rack is obtained, and the force distribution is taken as a force bearing input condition of the transfer rack. By analyzing the push force of a test bed, the force transmission route is measured, and support positions and quantity of truss rods set on the bottom of an upper ring beam are determined and taken as force output conditions of the transfer rack. Minimal uniform scattering difference of the force of the engine on the support face of the bottom of the upper ring beam after the force passes the transfer rack is taken as a target, a transfer rack structure based on force transmission symmetry is determined. According to the invention, the problem that larger torque is generated locally caused by non-coincidence of the force bearing point and the support transmission point is solved; loss in the force transmission process and effects on force transmission caused by deformation are reduced; and precision of force measurement is improved.