The invention discloses a high-viscosity PBX (Polymer Bonded Explosive) injection-compression molding method and device. The device is provided with an explosive charging barrel and an installing barrel, wherein an extrusion piston is arranged in the installing barrel and is connected to an air cylinder, the air cylinder can be used for controlling the extrusion piston to move up and down and stop, so that explosive slurry in the explosive charging barrel is pressed and injected into a mold to realize the explosive charging; the air cylinder is provided with two speed control valves so as to control the speed of the extrusion piston, and the device is aslo provided with a silencer, circulating water, a sealing ring and the like, so that the injection-compression molding device is further improved. The injection-compression molding device is used in the injection-compression molding method, so that the high-viscosity PBX charging is safely and efficiently realized. The injection-compression molding method and device can be used for solving the problem of poor rheological property of the high-viscosity PBX technology, can effectively ensure the controllability of internal quality of products when the explosive is charged in a complex structure in a large quantity, so as to obtain the explosive pouring parts with high filling quality; moreover, the charging process is rapid, safe, low in working noise, and simple and convenient to operate.