The invention relates to a real-time observation mechanism of flowing of fluid in a porous medium, which is characterized in that a shell comprises a front cover and a bottom board, wherein the middle of the front cover is hollow, and is communicated with an observation board, the back of the observation board is fixed with a porous mouldboard in parallel, and the porous mouldboard leans against the observation board through a back pressure mechanism, so that the porous mouldboard is gapless with the observation board at the front end; four openings are arranged at the periphery of the porous mouldboard, are introduced through shell arms, and are communicated with the side of the porous mouldboard through a buffer zone, the four openings form fluid inlets and fluid outlets, pressure fluid flows into pores in the porous mouldboard through the inlets, and flows out from the outlets, and the pores in the porous mouldboard are irregular pores which are arranged in array; and the observation board is a transparent body, and is fixedly provided with a camera, and the micro change of the fluid when the fluid passes through the porous mouldboard can be observed by the images shot by the camera. The invention discloses the real-time observation device which can observe the flowing of the fluid of the porous medium under the high-pressure, low-temperature (or high-temperature) state.