The invention relates to a hydraulic-driving mode based in-situ tensile / compression testing platform under a scanning electron microscope, and belongs to the field of electromechanics. The hydraulic-driving mode based in-situ tensile / compression testing platform under the scanning electron microscope comprises a hydraulic driving unit consisting of a hydraulic cylinder, an oil tank, an oil filter, a motor, a hydraulic pump, an overflow valve, a throttle valve and an electro-hydraulic servo valve, a load / displacement signal detection and control unit consisting of a displacement sensor and a pull and pressure sensor, and a clamping and supporting unit consisting of light bars, fixture body supporting racks, base linear bearings, pressure plates, a force sensor supporting rack and a specimen. The hydraulic-driving mode based in-situ tensile / compression testing platform under the scanning electron microscope has the advantages of small volume, compact structure, large output load, continuously variable transmission loading, and good structural compatibility with a microscopic imaging system with an open space structure, such as an optical microscope, a Raman spectrometer and an X-ray diffractometer and the like, and also can used for deep study on the micro-mechanical behavior and the deformation and damage mechanism of the specimen with a centimeter-level characteristic size under the action of tensile / compression loads by combination with the instruments.