With high frequency force balance (HFFB) technique, the rigid model of an actual grids-attached super-tall building with an approximate ellipse cross section was tested to obtain the effect of complex surrounding and attached grids on its base moments and torques. The results indicate that complex surroundings mainly have sheltering effect on mean value of aerodynamic force for the principle building; however it may increase fluctuating aerodynamic force for the principle building under some particular conditions. The tangential aerodynamic force on grids located in flow region of two sides of the principle building increases mean value and RMS of aerodynamic force in along-wind direction, and the increasing magnitude is determined by the area of the attached grids obstructing the flow. Moreover, the transformation in roughness induced by attached grids of the principle building would reduce vortex shedding strength, decreasing fluctuating aerodynamic force in cross-wind direction, and not affect RMS of fluctuating aerodynamic force. The fluctuating wind force on attached grids induced by periodic vortex shedding would partly offset fluctuating aerodynamic torque on main structure induced by fluctuating vortex-induced force, and not affect mean value of aerodynamic torque. These conclusions provide reference for the design of high-rise buildings.