The invention relates to a reflective terahertz time-domain near-field scanning microscope and belongs to the technical field of terahertz. The device comprise a femtosecond pulse laser, an optical fiber coupling beam splitter, a first optical fiber, a second optical fiber, a terahertz transmitting and receiving module, a delay line module, a visible light source, a visible light microscope, a three-dimensional translation sample stage, an adjustable voltage source, a current amplifier, a lock-in amplifier and a control computer. The terahertz transmitting and receiving module comprises a terahertz transmitting antenna, a terahertz receiving antenna and a laser coupling focusing element. The device is simple in structure and high in precision, the defect in the traditional far field imaging technology that the resolution ratio is low is overcome, and the device is capable of acquiring terahertz detection spectrum and scan images with micron order spatial resolutions.