As a key load-bearing and motion hub of the human body, the knee joint has features of high load capacity and strong stability. Structurally, it consists of the femur, ligaments, and tibia, with multiple ligaments connecting the femur and tibia to share vertical loads and convert part of the compressive stress on the tibia into tensile stress along the ligament direction, thereby preventing overload-induced buckling. Inspired by this biomechanical principle, this study proposes a multi-link bionic inverted pendulum, which consists of four symmetrically distributed C-shaped flexible arms and a rigid platform. This design disperses loads, mitigates stress concentration, and converts compressive stress on the pivot into tensile stress, significantly enhancing stability margins. A stability model is formulated, and the effects of disturbances, such as ground vibrations and centroid offset, are analyzed via simulation. Experimental results show that, under an 8 kg load, the system achieves a resolution better than 0.6 μN, a measurement range of 0.6~1 210 μN, and background noise below 1.42 μN/Hz1/2 in the 0.1 mHz~5 Hz band. Thrust measurements with a micro-Hall thruster show accurate response and a clear linear correlation among thrust, propellant flow, and discharge voltage. This knee-inspired bionic design offers a novel approach for developing high-precision micro-force measurement devices under heavy-load conditions.