This paper presents a three-component force sensor with MEMS gauges attached to its sensitive beams, which could be monolithically machined without assembly. All the sensitive areas of the dynamometer are designed on outer surfaces, which could contribute to the bond of gold wires onto the MEMS chips. Rough theoretical models are abstracted based on Euler beam theories, and Wheastone bridge circuits are provided according to the finite element simulations under loadings. Optimizations of dimensions are discussed to obtain isotropic sensitive outputs and minimized coupling errors. Finally with the help of simulation software, the safety factor and natural frequencies are also given. This design puts forward a solution with cost effective and maintenance friendly for both static and dynamic force measurements.