The invention discloses a uniform speed symmetrical 
uniaxial tension cell mechanical device for real-time in-situ observation. The device can realize uniform speed symmetrical 
uniaxial tension of cells culture on a transparent tension vessel, the location of the tension vessel middle part is constant in the tension process, and through coordination with temperature, 
humidity and 
carbon dioxide supply, real-time in-situ long-term observation for a few days 
on cells under a loading state can be realized. The device comprises: a 
power unit, a motion exeution unit, the transparent tension vessel, a clamping platform and a flexible telescopic air sac. The 
power unit achieves uniform speed symmetrical 
uniaxial tension of the transparent tension vessel through the motion exeution unit, the tension vessel is covered by the flexible telescopic air sac, and through 
environmental setting, the device realizes days of continuous culture and tensile loading of cells. The bottom surface of the clamping platform is processed into a 
size matching a 
microscope loading platform, and can be placed on the 
microscope loading platform stably. The device provided by the invention can realize uniform speed symmetrical uniaxial tension of the transparent tension vessel according to a set speed and tension length, and real-time in-situ long-term observation and multi-point observation.