A similarity simulation test device for solid-liquid coupling of a coal and rock mass, comprising: a test body carrying frame, a lateral carrying frame, a first loading mechanism, a second vertical loading mechanism, a third lateral loading mechanism, a hydraulic jack, and a stabilizing support beam, wherein: the similarity simulation test device for solid-liquid coupling of the coal and rock mass comprises one test body carrying frame, two lateral carrying frames, one first loading mechanism, one second vertical loading mechanism, two third lateral loading mechanisms, two hydraulic jacks, and one stabilizing support beam; both ends of the first loading mechanism are connected to respective first ends of the two hydraulic jacks, and respective second ends of the two hydraulic jacks are connected to the test body carrying frame; the lateral carrying frames are connected to the test body carrying frame, the second vertical loading mechanism, the third lateral loading mechanisms, and the stabilizing support beam; both ends of the second vertical loading mechanism are connected to the two lateral carrying frames, correspondingly; the third lateral loading mechanisms are connected to the two lateral carrying frames; and both ends of the stabilizing support beam are connected to the two lateral carrying frames, correspondingly, characterized in that: the test body carrying frame comprises: a sealing back plate, a lateral sealing plate, a water baffle, a sealing bottom plate, and a bearing bottom plate, on which coal and rock mass materials are laid; a box-shaped sealing space is formed by the sealing back plate, the lateral sealing plate, the water baffle, the sealing bottom plate, and the coal and rock mass materials laid on the bearing bottom plate; the first loading mechanism comprises a first loading pressure plate, a first loading rib plate, a water injection pipe, and a first loading connection trunnion; and the first loading connection trunnion is connected to the second end of the hydraulic jack; the first loading pressure plate is arranged within the box-shaped sealing space, and the water injection pipe is configured to inject water into the box-shaped sealing space; an extension/retraction stroke of the two hydraulic jacks is configured to be adjusted to change a value of water pressure to which the coal and rock mass is subjected in the box-shaped sealing space. the similarity simulation test device for solid-liquid coupling of the coal and rock mass comprises one test body carrying frame, two lateral carrying frames, one first loading mechanism, one second vertical loading mechanism, two third lateral loading mechanisms, two hydraulic jacks, and one stabilizing support beam; both ends of the first loading mechanism are connected to respective first ends of the two hydraulic jacks, and respective second ends of the two hydraulic jacks are connected to the test body carrying frame; the lateral carrying frames are connected to the test body carrying frame, the second vertical loading mechanism, the third lateral loading mechanisms, and the stabilizing support beam; both ends of the second vertical loading mechanism are connected to the two lateral carrying frames, correspondingly; the third lateral loading mechanisms are connected to the two lateral carrying frames; and both ends of the stabilizing support beam are connected to the two lateral carrying frames, correspondingly, characterized in that: the test body carrying frame comprises: a sealing back plate, a lateral sealing plate, a water baffle, a sealing bottom plate, and a bearing bottom plate, on which coal and rock mass materials are laid; a box-shaped sealing space is formed by the sealing back plate, the lateral sealing plate, the water baffle, the sealing bottom plate, and the coal and rock mass materials laid on the bearing bottom plate; the first loading mechanism comprises a first loading pressure plate, a first loading rib plate, a water injection pipe, and a first loading connection trunnion; and the first loading connection trunnion is connected to the second end of the hydraulic jack; the first loading pressure plate is arranged within the box-shaped sealing space, and the water injection pipe is configured to inject water into the box-shaped sealing space; an extension/retraction stroke of the two hydraulic jacks is configured to be adjusted to change a value of water pressure to which the coal and rock mass is subjected in the box-shaped sealing space. the test body carrying frame comprises: a sealing back plate, a lateral sealing plate, a water baffle, a sealing bottom plate, and a bearing bottom plate, on which coal and rock mass materials are laid; a box-shaped sealing space is formed by the sealing back plate, the lateral sealing plate, the water baffle, the sealing bottom plate, and the coal and rock mass materials laid on the bearing bottom plate; the first loading mechanism comprises a first loading pressure plate, a first loading rib plate, a water injection pipe, and a first loading connection trunnion; and the first loading connection trunnion is connected to the second end of the hydraulic jack; the first loading pressure plate is arranged within the box-shaped sealing space, and the water injection pipe is configured to inject water into the box-shaped sealing space; an extension/retraction stroke of the two hydraulic jacks is configured to be adjusted to change a value of water pressure to which the coal and rock mass is subjected in the box-shaped sealing space.