Simulating the real boundary conditions of a test specimen in a structure is one key problem determining the correction of the structural test results，i.e.，to realize the accurate loading of commands of multi-degree-of-freedom system on boundary loading point. Civil engineering structures（or components）generally have large vertical stiffness，and there is a strong coupling between various degrees of freedom under gravity load. The traditional loading method with actuator controlled independent has low accuracy，and even loading control becomes unstable during test. To solve this problem，a flexible multi-degree-of-freedom force-displacement hybrid control（FMFDC）strategy is developed，which can flexibly design the control mode（force or displacement）of the degrees of freedom at control points and the actuators according to the characteristics of test specimen and test equipment，propose the general stiffness matrix to equivalent model the material nonlinearity of the test specimen approximately，and design the force-displacement transform matrix，then use the coordinate transformation Jacobian matrix to linearize the geometric nonlinearity of the loading device. The proportional-integral-derivative control method（PID control method）then minimizes the steady-state error of every degree of freedom to satisfy the accuracy requirements and finally realizes the MDOF coordinated loading. To validate FMFDC，both a six degrees of freedom table，and an in-plane three degrees of freedom loading platform are used. Cyclic tests on a small-scale steel tube specimen and a full-scale steel column are conducted respectively to verify the feasibility and applicability of this control method.