The invention relates to a reciprocating plunger pump packing seal structure applicable to a high-temperature medium. The reciprocating plunger pump packing seal structure is arranged between a seal chamber of a reciprocating plunger pump and a plunger, and the seal chamber of the reciprocating plunger pump is formed by connection of a packing box and a cylinder jacket. The packing seal structurecomprises an adjusting ring, a thrust ring, a seal packing ring, a guide ring and a thrust collar. A conical ring cavity is formed between the interior of the adjusting ring and the plunger, the thrust ring and the seal packing ring are arranged in the conical ring cavity, the outer surface of the seal packing ring is a conical surface fitting the conical ring cavity, the guide ring and the thrustring are both arranged between the plunger and the packing box, and one end of the guide ring is abutted against the seal packing ring while the other end is abutted against the thrust collar. By adoption of a special packing compression part and a seal part in a special shape, packing compression quantity can be comprehensively and uniformly adjusted according to medium temperature, stress uniformity and abrasion uniformity of the seal part can be achieved, the service life is prolonged, and operability and safety and reliability in operation are improved.