This thesis describes the design, construction and application of a novel magneto-optical tweezers with super-resolution fluorescence microscopy for manipulation, force/torque measurement and imaging of single biomolecules. The optical tweezers component offers force or position clamping in three dimensions. The 3D-printed magnetic tweezers is designated for rotation in the vertical plane. The separation of rotation from force transduction results in the capability of precise torque measurement. The filamentous biomolecules to be used in the device will lie in a transverse direction in the imaging plane to allow fluorescence imaging with techniques including Blinking assisted Localisation Microscopy (BaLM) and total internal reflection fluorescence microscopy (TIRF). Also included are features such as acousto-optic deflection and multiplexing of laser traps, interferometry based tracking with quadrant photodiode and piezoelectric actuated nanostage for active feedback. These tweezers have been developed to enable direct observation of molecular topological transformation and protein binding event localisation with mechanical perturbation, which traditional tweezers could not achieve.