The invention relates to a loose sandstone hydraulic fracturing simulating device capable of real-time observing the fracture shape. The loose sandstone hydraulic fracturing simulating device comprises a chassis, an outer wall barrel, a flange, a transparent panel, a flange outer ring, a seal cover and a top cover plate; the outer wall barrel is located on the chassis, the flange is installed in the outer wall barrel, and a core is placed on the top face of the flange; the transparent panel is placed on the top face of the core, the transparent panel is sleeved with the flange outer ring, andthe seal cover is placed on the top of the outer wall barrel; the top cover plate is placed on the top of the seal cover, and the chassis tensions the top cover plate through a bolt; an annular hollowcavity is formed between the flange, the core, the flange outer ring and the outer wall barrel; an oil injecting hole communicates with the annular hollow cavity is formed in the outer wall barrel, apressure relief hole which communicates with the annular hollow cavity is formed in the chassis, and a fracturing liquid injecting hole which communicates with the position where the core locates isformed in the chassis; and a groove is formed in the face where the flange outer ring makes contact with the core, the groove is connected with one end of a communicating vessel through a vent hole inthe flange outer ring, and the other end of the communicating vessel is connected with a vent hole arranged in the bottom of the chassis.