The invention discloses a variable-angle bulk filling material testing device which mainly comprises a variable-angle structure, a compaction box body and a base. The variable-angle structure comprises a driving angle setting device consisting of a guide rod, a tooth inserting plate and a pressure-bearing variable-angle plate and a driven angle pressing device consisting of a variable-angle pressing head and a clamping sleeve block. The lower part of the base is hinged with the driving angle setting device, the upper part of the base bears the compaction box body, the angle transformation is realized by changing the position of the pressure-bearing variable-angle plate on the guide rod, and the angle of the variable-angle pressing head is correspondingly set, so that the variable-angle pressing head is always jointed with the compaction box body. The variable-angle bulk filling material testing device is simple in structure and convenient to operate, and can simulate the pressure-bearing mechanical properties of bulk filling materials such as gangue, aeolian sand and loess during filling and mining of coal seams at different inclination angles.